i left my umbrella in my room.Do you mind waiting ----i come

i left my umbrella in my room.Do you mind waiting ____i come back to get it?
i left my umbrella in my room.Do you mind waiting ____i come back to get it?
i left my umbrella in my room.Do you mind waiting ____i go back to get it?(第二小题)
第一题我知道，刚才点快了。第二小题原来是2005年江西省中考题，答案为while ,选项没这个，能不能用after.
第一题是come back 用until第二题题目都不同。该题没until选项也没有while
A.if B before C.after D.unless
现在的题目是第二小题
选项只有A.if B before C.after D.unless可不可以选C。
那中考题的选项中也有if啊。都不能选啊。