A.Can you go outside?

B.Can I go outside?

C.How about you?

【答案】B

【解析】

想问自己能否做什么要用can引导一般疑问句，A. Can you go outside?你能出去吗？B. Can I go outside?我能出去吗？C. How about you?那你呢？AC不符合语境，故选B。