单项选择题
Passage One Questions 16 to 18 are based on the conversation you have just heard.
What message did the researcher intend to convey to parents（）
A．They should make sure their children are always punctual for school.
B．They should ensure their children grow up in a healthy environment.
C．They should help their children accomplish high-quality work.
D．They should see to it that their children have adequate sleep.