The correct answer is option 1, Rashtrakuta Ruler Krishna I. The famous Shiva temple at Ellora was built during the Rashtrakuta dynasty, which ruled parts of present-day India from the 8th to the 10th century. The construction of the temple complex at Ellora took place between the 6th and 8th centuries, and it is a UNESCO World Heritage Site. The temple is dedicated to Lord Shiva and is known as the Kailasa Temple. It is renowned for its magnificent rock-cut architecture and intricate carvings. Option 2, Mauryan Emperor Ashoka, is not correct as Ellora was built much later than the Mauryan Empire. Option 3, Gupta King Samudra Gupta, is also not correct as Ellora was constructed after the Gupta Empire. Option 4, Chalukyan King Pulikeshi II, is also not correct as it was the Rashtrakuta Ruler Krishna I who built the Shiva temple at Ellora.