(A) Both, (A) and (R) are true and (R) is the correct explanation of (A).
India's central geographical position in the Indian Ocean connected East Asia, West Asia, and Europe, making it a crucial node in sixteenth-century trade flows.
The Assertion is correct — India was a vital hub in Indian Ocean trade. The Reason correctly explains why: its geographical location acted as a bridge between East Asia, West Asia, and Europe. Since R directly and logically explains A, option (A) is the right choice. In Assertion-Reason questions, always check if R is not just true but also the cause of A.