Are you doing anything . . . . . . . . the weekend? A. at B. in C. on D. None of the above

The correct answer is: on.

The word “on” is used to refer to a specific day or date. In this case, the question is asking about the weekend, which is a specific period of time that includes two days: Saturday and Sunday. Therefore, the correct answer is “on”.

The other options are incorrect because they do not refer to a specific day or date. The word “at” is used to refer to a specific time. The word “in” is used to refer to a specific period of time that does not include a specific day or date. The word “none of the above” is incorrect because it is not an option.