The boy has rung the bell.

The correct answer is: The boy has rung the bell.

The other options are incorrect because they do not accurately describe the action of the boy.

• Option A, The bell has been rung by the boy, is incorrect because it implies that the bell was rung by someone other than the boy.
• Option B, The bell was being rung by the boy, is incorrect because it implies that the boy was in the process of ringing the bell, but did not finish.
• Option C, The bell was rung by the boy, is incorrect because it implies that the boy rang the bell at some point in the past, but not necessarily recently.
• Option D, The bell has been being rung by the boy, is incorrect because it implies that the boy has been ringing the bell for an extended period of time.

The sentence “The boy has rung the bell” is in the simple past tense. This tense is used to describe actions that happened at a specific time in the past. In this case, the boy rang the bell at some point in the past, and the action is now complete.