Before having solid food, how will an infant respond to a drop of lemon juice put in her mouth?
a. She will smile because babies have a preference for novelty.
b. She will respond with a curious expression and develop a preference for that taste.
c. She will grimace because the reaction is present at birth.
d. She will not respond because she has no experience with food yet.
Answer: C. She will grimace because the reaction is present at birth.