LSAT 10 | Section 1 | Logical Reasoning: Q24

LR Question 24 Explanation

QUESTION TEXT: The body of anyone infected by virus X will, after a week, produce …

QUESTION TYPE: Most Strongly Supported

FACTS:

• People infected with virus X begin producing antibodies after a week.
• These antibody levels increase steadily for about a year.
• There is a test that can measure antibody count, and during the first year, it can estimate how long ago infection occurred (within a month).

ANALYSIS: We know antibodies don’t appear immediately, they begin after one week. So if someone is infected and tested too early, they’ll likely show no antibodies.

___________

1. We don’t know that antibodies stop increasing once the virus is defeated, or even whether the virus is ever defeated.
2. The stimulus says the test is helpful, but it doesn’t claim it’s the only way to detect infection.
3. Nothing in the stimulus talks about how the body decides when to produce antibodies. Only that it does after virus X infection.
4. We’re told antibodies increase for about a year, not indefinitely. This answer contradicts that limit.
5. CORRECT. If antibodies don’t appear until a week after infection, then for a short time, a person will test negative on the test despite being infected.