单选题 A possible reason that a child having an unhappy relation with his/her mother will not be affected by maternal separation at 6 to 9 months is that ______.

A、 the struggle between trusting and mistrusting has reached a climax
B、 the child sees himself/herself as being separate from the environment
C、 the child's sense of trust is destroyed
D、 no sense of trust has ever developed

【正确答案】 B

【答案解析】[解析] 本题可参照第四段，从中可知B项为正确答案。