I got the answer right but im not sure the way I got there is correct. Because answer B starts with "Not" I applied the Negate the necessary rule, and negated town's artistic circle, then because we learned that "All" implies "some" I changed it into a some statement but im not sure if this line of thinking is correct

if we apply the example from the students can read with 20 students in the class and "some" indicates that there must be true that at least one for the lower boundary, is the negating addressing what must be false then that 0 can read?

I understand the difference between Negating conditional statements and taking the Contrapositive but in a question how would I know which method to use if they use the same indicator words (e.g. If-then)?

my only question is we are taught that when something is not something it does not mean polar opposites e.g. uncomfortable public space in the previous examples was used as /comfortable, and here its rent less than 10 = /10+ so when do we apply the rule of not assuming polar opposites and using polar opposites to make inferences.

I found this much more easier than the exotic birds/tropical fish one even though this is rated higher in difficulty lol

is it bad that I used a more simple conditional lawgic:

/traffic flow increased → /invested in computer tech AND /financial predicament resolved

and I just looked for the answer choice that said the same thing or its contrapositive. And only B made the most sense based on this lawgic