Write an incorrect answer to the given question based on the associated fact. You are also provided with the correct answer to the given question. Make sure that your incorrect answer is relevant and similar to the associated fact. Also, try to make the incorrect answer similar to the correct answer so that distinguishing the correct answer from the incorrect answer is not very easy. Make sure you don't accidentally provide another correct answer! Also, make sure they sound reasonable (e.g., might be on a school pop quiz). A good incorrect answer can be constructed using words associated with the question, but not the correct answer. For example, for the question "What helps plants survive?", using words like "weeds", "vase", "bee" (associated with "plant"), or "first aid", "parachute", "accident" (associated with "survive") etc. Your incorrect answers make the question hard, so these results in good incorrect answers.

Fact: antigens are a group of atoms that the immune system recognizes as foreign to the body. 
Question: what type of antigens does the immune system recognize as foreign to the body? 
Correct Answer: group of atoms.
h2o.

Fact: Many nerve pathways link the brain sites with motor neurons throughout the body. 
Question: Many nerve pathways link the what with motor neurons throughout the body? 
Correct Answer: brain sites.
brainiacs.

Fact: Howling is used to caution other wolves by wolves. 
Question: What kind of sound is used by wolves to caution other wolves? 
Correct Answer: howling.

a barking sound.