How did the monsoon help ancient sailors return to India?

Sailors waited for the Southwest monsoon, which blew towards the Indian subcontinent, providing the necessary wind power for the return leg.

Maritime Trade: Why India Dominated the Bay of Bengal

Q: India maintained its early cultural contacts and trade links with Southeast Asia across the Bay of Bengal. For this pre-eminence of early maritime history of Bay of Bengal, which of the following could be the most convincing explanation/explanations?

The most convincing explanation for India's maritime pre-eminence in the Bay of Bengal was the monsoon winds. These seasonal winds facilitated predictable and efficient sea voyages to and from Southeast Asia.

ID: ANC_HIS_PM_PG_2011_14 Ref: Standard Educational Reference

India maintained its early cultural contacts and trade links with Southeast Asia across the Bay of Bengal. For this pre-eminence of early maritime history of Bay of Bengal, which of the following could be the most convincing explanation/explanations?