Self-study
There have been no new cases of naturally occurring polio in North America in recent years. ███ █████ ███ █████████████ ██ ███ █████ ██ █████ ████ ████ ██ █████ ████████ ███ ██████ ██ ███ ████████ ████████████ ████ ████ █████ ███████ ██████ ████████████ ███████████ █████ ███████ █████ ███ ████ █████████ █████ █████████████ █████ ███ ███ ██████ ██ █████ ██ ██████████████████ █████ █████ ██ █████ ███████ ██ ██ ████ ██ ██████ ████ ███ ██ ███ ██ ███ ████ ████████ ████ █████ ███████ ███ █████ ████████ █████████
Summarize Argument
IPV should be the most commonly used polio vaccine for North American children, instead of OPV. OPV causes all new cases of polio each year in North America, and IPV would reduce the number of cases by half.
Notable Assumptions
The author assumes that IPV does not have serious side effects that make it undesirable for use on most children—side effects that may outweigh the benefit of decreasing the number of cases of live polio a year. Furthermore, the author assumes that there are no other significant undesirable consequences that could arise from the proposed switch.
19.
Which one of the following, ██ █████ ████ ███████ ███ █████████
a
If IPV replaces ███ ██ ███ ████ ████████ ████ █████ ████████ ██ █████ █ ███ ███ █████ ██ █████████ █████████ █████ ██ █████ ███████ ████ ██████ ████ █████
This weakens the argument. It exploits the author’s assumption that there are no significant undesirable consequences that could arise from the switch. (A) says if IPV replaces OPV, naturally occurring polio would result—something which has not occurred in recent years.
b
The vast majority ██ █████ ██ █████ ██████ ██ ███ ████ ████████ ██ ████████ ████ ███████████ ███ ███████████ ████████████████ ██████████
This does not affect the argument. The author advocates for a switch to IPV to reduce the annual number of polio cases. The specific characteristics of these cases—such as whether the affected children had undiagnosed immunodeficiency disorders—do not weaken the argument.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion. In other words, it feints an attack on the premises or conclusion. If correlation is present, the answer choice is often merely an outlier datapoint, which is actually entirely consistent with the correlation.
c
A child's risk ██ ███████████ █████ ████ ███ ███ ████ █████████ ██ █ ██ ███ ████████ █████ ██ █████████████ ████ ████ ███ ████ ██ █████ ██████ ██ ██████████
This does not affect the argument. The author does not dispute the idea that the risk is slight; rather, the author argues that the risk could be further reduced by switching to IPV.
d
Although IPV is █████████ ██ ████ ████████ ████████ ████ █████████ ████ █████████████ █████ ████████████ ████████ ███ ████
This does not affect the argument. The author’s argument is supported solely by evidence from North America, and the conclusion is specific to North America as well. What other continents or countries are doing is not relevant.
e
IPV, like most █████████ ███████ █ ██████ ████ ██ ████████ ████████ ██ ████████ ████ ████████████ ████████ ████ ██ █████████
This does not affect the argument. Both OPV and IPV are vaccines—this would apply to both equally.