The correct option is B Both A and R are true but R is not the correct explanation of A.
The Darasuram temple near Kumbakonam is a later Chola period temple dedicated to Lord Shiva. Lord Indra had a white elephant named Airavata. One day, Airavata lost his natural colour as a result of sage Durvasa's curse. He came to take a bath in the temple tank of Darasuram. After the bath, Airavata regained his natural colour because of Lord Shiva's blessings, and Lord Shiva became the God of Airavata or Airavateswara. The temple came to be known as the Airavatheswara temple.