The Shailendra kings who had close contacts with the Indian rulers were followers of which of the following religions?

The Shailendra dynasty was a prominent ruling family that flourished in Java (modern-day Indonesia) and Sumatra from the 8th century onwards. They were great patrons of Mahayana Buddhism and constructed magnificent monuments, including the world-famous Borobudur stupa.
The Shailendra rulers maintained active diplomatic, religious, and cultural contacts with prominent Indian kingdoms. For instance, the Nalanda copper-plate inscription records that the Shailendra king, Balaputradeva, built a monastery at Nalanda and requested King Devapala of the Pala Empire of Bengal to grant five villages for its maintenance.