The correct answer to this open question is the following.
What made Chinese exploration of the Indian Ocean possible was its capacity to build good ships and advances in navigation.
In the history of ancient China navigation, there was one individual who took the lead in Chinese exploration in the 1400s. His name: Zheng He. He had the right skill to lead many expeditions across the Indian Ocean due to the Chinese knowledge to build ships that resisted harsh oceanic conditions and innovative navigation skills.