Explanation:

The correct answer is "Will you have done" because it is a future perfect tense which refers to an action that will be completed in the future before a certain time. In this case, the time is 3 o'clock which is in the future.

Future perfect tense is formed by using "will have + past participle" of the main verb. In this sentence, "done" is the past participle form of "do". Therefore, the correct sentence is "will you have done the shopping by 3 o'clock?"

Detailed explanation:

- Future perfect tense: It is a tense that is used to describe an action that will be completed at a certain time in the future. It is formed by using "will have + past participle" of the main verb.
Example: By 6 pm tonight, I will have finished my work.

- Use of "will have done": In the given sentence, "will you have done" is used to ask whether the shopping will be completed before 3 o'clock or not.
Example: Will you have finished your homework by the time I come home?

- Past participle form of "do": The past participle form of "do" is "done". In the given sentence, "done" is used after "have" to form the future perfect tense.
Example: She has done her homework.

- Time reference: In the given sentence, the time reference is "by 3 o'clock". It means that the shopping should be completed before 3 o'clock.

Therefore, the correct sentence is "Will you have done the shopping by 3 o'clock?"