The correct answer is: A. ‘War and Peace’ was written by Leo Tolstoy.
The other options are incorrect because they do not accurately reflect the tense of the sentence. Option B, “War and Peace is written by Leo Tolstoy,” is in the present tense, but the sentence is about a historical event that happened in the past. Option C, “War and Peace will be written by Leo Tolstoy,” is in the future tense, but the sentence is about something that has already happened. Option D, “War and Peace was being written by Leo Tolstoy,” is in the progressive tense, but the sentence does not specify that the writing was ongoing.
The sentence “Leo Tolstoy wrote ‘War and Peace'” is in the simple past tense, which is the most common tense used to talk about historical events. This tense indicates that the action of writing the book was completed in the past.