The Kailasa temple at Ellora was constructed by?

The correct answer is Option (2) → Rashtrakutas

The Kailasa temple (Cave 16) at Ellora, near Aurangabad in Maharashtra, was built by the Rashtrakuta king Krishna I in the 8th century AD. It is dedicated to Shiva and was cut from a single rock, working down from the top of the hill, so the whole temple with its courtyard is one carved block. It is one of the largest monolithic rock-cut structures in the world and part of the Ellora Caves World Heritage Site.

Note: NTA dropped this question in its Final Answer Key. For the benefit of students and to ensure a single answer, the question has been slightly modified.