Which monsoon would a trader rely on to sail from africa to india

Arabian Sea Branch the south west monsoon winds.

Explanation:

The Vasco da Gama a Portuguese explorer who set sail on his ship from the southern tip of Africa and landed on India and it took him about 10 months to set sail.  As the winds move in a northeasterly direction India the Arabian sea branch first touches the coast the Kerala coast. to that of the western ghats. Hence the Indian ocean trade networks of the ivory and the gold that came firme the African coasts are thus marked the trade winds that flow from the southeast called the Arab monsoon trades.