Option 1 states that the olive ridley turtles are the smallest and most abundant sea turtles found in the world. This statement is correct. Olive ridley turtles are indeed the smallest species of sea turtles and they are also considered the most abundant.

Option 2 states that the olive ridley turtles live in the warm waters of the Pacific, Atlantic, and Indian Oceans. This statement is also correct. Olive ridley turtles are known to inhabit the warm waters of these three oceans.

Option 3 states that the Coromandel Coast in India is the largest mass nesting site for the olive ridley turtles. This statement is correct as well. The Coromandel Coast in India is indeed known to be the largest nesting site for olive ridley turtles, with thousands of turtles coming ashore to lay their eggs.

Therefore, the correct answer is option 2: 1 and 2 only. Olive ridley turtles are the smallest and most abundant sea turtles found in the world, and they live in the warm waters of the Pacific, Atlantic, and Indian Oceans.