#23 - An air traveler in Beijing cannot fly to Lhasa without first flying to Chengdu. Unfortunately,

[Administrator]

Complete Question Explanation

Parallel Reasoning, Sufficient and Necessary. The correct answer choice is (B).

Answer choice (A):

Answer choice (B): This is the correct answer choice.

Answer choice (C):

Answer choice (D):

Answer choice (E):

This explanation is still in progress. Please post any questions below!

[saiffshaikhh@gmail.com]

I thought C was confidently the correct answer choice, did I match the variables incorrectly? Did C have only two variables whereas the stimulus and B, both had 3 ?!

[Luke Haqq]

Hi saiffshaikhh!

The stimulus has the follow conditional reasoning in it:

Lhasa Chengdu
Chengdu Xian

The stimulus then concludes:

Lhasa Xian

This is valid conditional reasoning. Answer choice (B) parallels this reasoning. It has the following premises:

Yellow Green
Green White

Then it reaches the following valid conclusion:

Yellow White

So the stimulus and answer choice (B) both reflect how one can arrive at the inference A C based off the chain A B C.

The problem with answer choice (C) is the second sentence. Note that it only states that a powerful microscope "can" be used to examine the spores of a mushroom. This would be a contender answer if that was instead "must."