Which waterway separates India from Sri Lanka?

The Palk Strait is the primary waterway separating the Indian state of Tamil Nadu from the Mannar district of Sri Lanka [1][t1]. It is a shallow sea, approximately 30 km wide at its narrowest point, connecting the Bay of Bengal in the northeast to Palk Bay and the Gulf of Mannar in the southwest [c1][t8]. Geographically, it is bounded by the Indian peninsula to the west and the island of Sri Lanka to the east [t4][t7]. Other options are incorrect as the Eight Degree Channel separates the Maldives from India's Minicoy Island [t3], the Ten Degree Channel separates the Andaman Islands from the Nicobar Islands [t2][t3], and the Andaman Sea is a marginal sea of the Indian Ocean located to the east of the Andaman Islands [c2]. The Palk Strait remains a significant maritime boundary and historical site, containing the chain of sandbars known as Adam's Bridge [c4][t7].

Sources

1. [1] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > India-Sri Lanka Boundary > p. 50