Please choose the correct answer to the question: A student notices dogs have more fleas in the summer than in the winter. Based on these observations, which is the most logical question for the student to investigate?

Answer1: How does wind affect the amount of fleas on dogs? Answer2: How does diet affect the amount of fleas on dogs? Answer3: How does rain affect the amount of fleas on dogs? Answer4: How does temperature affect the amount of fleas on dogs?

Answer format: answer1/answer2/answer3/answer4
Answer: answer4