单项选择题

Questions 11 to 13 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions. Now listen to the passage. What can we learn from the findings of the study

A.Family-oriented day-care centers will surely increase.
B.Infants benefit more from being with familiar babies.
C.Even one-year-old babies can become friends.
D.Children are comfortable with their baby-sitters.