PrepTest 114

Incorrect. Higher risk of stroke and higher homocysteine levels are correlated.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Eating more fruits and veggies lowers risk of stroke
Fruits and veggies have a lot of folic acid
Low folic acid equals high homocysteine
High homocysteine equals more blocked arteries

Answer Anticipation:
This entire stimulus is about the relationships between the different elements—fruits/veggies, folic acid, homocysteine, blocked arteries, and risk of stroke. However, not all of the relationships are positive in that higher levels of one leads to higher levels of another. To make a list:
Positive relationships - Fruits/veggies and folic acid; homocysteine and blocked arteries
Inverse relationships - Fruits/veggies and risk of stroke; folic acid and homocysteine

And chaining together these relationships:
More fruits/veggies = More folic acid = Less homocysteine = Fewer blocked arteries (= Lower risk of stroke)

Fewer fruits/veggies = Less folic acid = More homocysteine = More blocked arteries (= Higher risk of stroke)

Note that we put the last relationship inside parentheses because it's more implied than it is stated.

Let's find an answer that lines up with this chain.

Answer Explanation:
More fruits/veggies are correlated with both more folic acid and a lower risk of stroke, so this answer is correct.

Key Takeaway:
When these kinds of positive and inverse/negative relationships are mashed together, make sure you get the direction of each relationship correct. As we saw here, essentially the whole thing was keeping track of what was positively and negatively correlated!

Incorrect. Higher homocysteine levels are correlated with a higher propensity for blocked arteries, not a lower one.

Incorrect. More folic acid is correlated with fewer blocked arteries.

Incorrect. "Prevented" is too strong here—there's no sign that strokes can be prevented, just the risk can be lowered.