The correct answer is: C. was breaking
The sentence “Every day of last week my aunt ___ a plate” is in the past progressive tense. The past progressive tense is used to describe an action that was happening over a period of time in the past. In this case, the action is “breaking a plate.” The aunt was breaking a plate every day of last week.
The other options are incorrect because they do not describe an action that was happening over a period of time in the past. Option A, “breaks,” is in the simple present tense. The simple present tense is used to describe an action that happens regularly or repeatedly. Option B, “broke,” is in the simple past tense. The simple past tense is used to describe an action that happened at a specific time in the past. Option D, “none of these,” is incorrect because it is not a grammatically correct sentence.