单选题 The topic of the 4th paragraph is that ______.

A、 one problem of loneliness is a person's social contacts
B、 we depend on various people for different reasons
C、 lonely people don’t have many social problems
D、 lonely people don’t have many friends

【正确答案】 A

【答案解析】[解析] 第四段主要谈孤独与社会交往的关系。故本题答案为A。