Why Correct: The Indian Peninsula is bounded by the Arabian Sea to the southwest, the Indian Ocean to the south, and the Bay of Bengal to the southeast, forming a continuous water boundary on three sides.
Distractor Analysis: South and East describes only two sides, missing the Arabian Sea on the southwest. South and West incorrectly includes lakes and rivers, not the open sea. East and West incorrectly suggests water on both sides of the peninsula's northern connection to the mainland.
Takeaway: The Indian Peninsula specifically refers to the landmass south of the Narmada River and the Satpura Range, distinct from the entire Indian subcontinent.