Self-study
Support People who are good at playing the game Drackedary are invariably skilled with their hands. ████ ██ █ ████ █████████ ███████████ ██████████ ████ █████ ████ █ ████ ██████████ ███████
Method of Reasoning
The author concludes that Mary would be good at Drackedary. His reasoning is that, if you’re good at Drackedary, you’re skilled with your hands. And Mary is a competent watchmaker. 
Identify and Describe Flaw
The author’s reasoning is clearly flawed in two respects. Firstly, he commits the cookie-cutter flaw of confusing necessary and sufficient conditions. Just because being skilled with your hands is necessary to be good at Drackedary doesn’t mean it’s also sufficient. (For example, all apples are fruits, but not all fruits are apples.)
Secondly, it’s not clear that Mary is skilled with her hands just because she’s a competent watchmaker.
15.
The flawed pattern of reasoning ██ ███ ████████ █████ ██ ████ ███████ ██ ████ ██ █████ ███ ██ ███ ██████████
a
People with long ████ ████ ████ ████████ ████████ ██ ███████ ██████ ███ ████ █████ ██████████ █████ █████ ████ █ ████ ███████
This is valid reasoning, unlike the stimulus. (A) defines a conditional relationship (if long legs, then good runner) and properly applies it. By contrast, the stimulus commits the cookie-cutter flaw of confusing necessary and sufficient conditions, and makes an unwarranted assumption.
b
People who write ███ █ ██████ ██████████ █████ ████████ █████ ███ ████ █ █████████ ████████ ███ ████ ██████ ██████████ █████ ██████ ████████
This is the wrong flaw. (B) fails to consider that someone can be a published novelist without writing for a living. In other words, it makes an unwarranted assumption—but if the assumption were correct, the conclusion would follow. The stimulus also makes an unwarranted assumption (watchmakers are good with their hands). But it does so while furthermore committing the cookie-cutter flaw of confusing necessary and sufficient conditions, unlike (B). (Even if Donna were good with her hands, it wouldn’t follow that she’d be good at Drackedary.)
c
All race car ███████ ████ ████ █████████ █████ ██ █ ████████ █████ ██████ ███████ ██████████ █████ █████ ████ █ ████ ████ ███ ███████
(C) concludes that Chris would be good at driving race cars. The reasoning is that, if you can drive race cars, you have good reflexes. And Chris is a table tennis champion.
This reasoning has the same two flaws as the stimulus. Firstly, (C) commits the cookie-cutter flaw of confusing necessary and sufficient conditions. Just because having good reflexes is necessary to drive race cars doesn’t mean it’s also sufficient. Secondly, it’s not clear that Chris has good reflexes just because he’s a table tennis champion.
d
The role of █████ █████ ██ █ ████████ ████ ██ █████ ██████ ██ ██ ███████████ ██████ █████ ███ ██████ █████ █████ ██ ████████ █████ ███ ██████ ██████████ █████ ████ ██ ██ ███████████ ██████
This is the wrong flaw. (D) unjustifiably jumps from high probability (Santa is often played by an experienced actor) to absolute certainty (this Santa must be experienced). By contrast, the stimulus commits the cookie-cutter flaw of confusing necessary and sufficient conditions, and makes an unwarranted assumption.
e
Any good skier ███ █████ ██ █████████ ███████████ █████ ██ █ ███████████ ██████ ██████████ █████ █████ █████ ██ █████████ ██ █ ███ ██ ████
This is the wrong flaw. (E) unjustifiably conflates learning to ice-skate eventually with learning to ice-skate in a day or two. By contrast, the stimulus commits the cookie-cutter flaw of confusing necessary and sufficient conditions, and makes an unwarranted assumption.