问题详情

According to the comprehensive input theory, "i +1" refers to

A．the current level of the learner"s interlanguage.

B．a little more advanced than current level of the learner"s language knowledge.

C．a little more than the current quantity of the input the learner received.

D．the current quantity of the input the learner received.

请帮忙给出正确答案和分析，谢谢！