Question

what caused peanut allergies to go down?
a david hills research on the immune system
b leaps decision to stop giving babies peanuts
c the 2017 guidelines from u.s. health organizations

Explanation:

To determine what caused peanut allergies to go down, we analyze each option:

• Option A: David Hill's research on the immune system is more about understanding the immune system related to allergies but not the direct cause of the decrease in peanut allergies.
• Option B: LEAP's decision to stop giving babies peanuts would likely not cause a decrease in peanut allergies; in fact, early introduction of peanuts (opposite of stopping) is associated with reducing allergies.
• Option C: The 2017 guidelines from U.S. health organizations likely recommended early peanut introduction to babies, which has been shown to reduce the risk of peanut allergies, thus leading to a decrease in peanut allergies.

Answer:

C. the 2017 guidelines from U.S. health organizations