根据法律规定，有些营业性活动场所是禁止未成年人进入的。这一规定[ ]

A．体现了对未成年人的社会保护

B．体现了对未成年人的家庭保护

C．伤害了营业性场所的合法利益

D．不利于未成年人全面健康发展

You have a big mouth, Li Fei. You ____ have told everybody the secret. [ ]

A. can't

B. mustn't

C. shouldn't

D. mightn't