________ is separated from mainland India by a narrow channel of sea formed by the Palk Strait and the Gulf of Mannar.

Introduction / Context:
Physical and political geography of the Indian subcontinent includes important straits and gulfs that separate India from its neighbours. The Palk Strait and the Gulf of Mannar together form a narrow stretch of sea between India and the island nation of Sri Lanka. This is a frequently asked fact in school and competitive exams.

Given Data / Assumptions:

• The question describes a narrow channel of sea formed by the Palk Strait and the Gulf of Mannar.
• It states that this channel separates mainland India from another country.
• Options are Sri Lanka, Myanmar, Bangladesh, and Pakistan.

Concept / Approach:
The Palk Strait lies between the southeast coast of India (Tamil Nadu) and the northwest coast of Sri Lanka. To the south of this, the Gulf of Mannar opens into the wider Indian Ocean between India and Sri Lanka. Together they form the marine boundary between these two countries. Myanmar lies to the east of India separated by land borders and the Bay of Bengal further away. Bangladesh is located to the east of India and is not separated from India by a strait. Pakistan lies to the northwest of India, again connected by land rather than by a narrow channel of sea.

Step-by-Step Solution:
Step 1: Recognise that the Palk Strait is commonly mentioned in relation to Sri Lanka and India.Step 2: Recall that the Gulf of Mannar is also situated between the southeastern Indian coast and Sri Lanka.Step 3: Understand that together these water bodies form a narrow sea channel separating mainland India from an island state.Step 4: Identify Sri Lanka as the island country just to the south of India.Step 5: Compare with the other options, which are all mainland neighbours connected by land, not solely by a sea channel.Step 6: Select Sri Lanka as the correct answer.

Verification / Alternative check:
Maps of South Asia clearly show Sri Lanka lying just off the southeastern tip of India, with a narrow blue strip marked as Palk Strait and the Gulf of Mannar between them. No such straits or gulfs separate India from Myanmar, Bangladesh, or Pakistan in this specific way. This visual confirmation supports the choice of Sri Lanka.

Why Other Options Are Wrong:
Myanmar borders India over land in the northeast and is separated in part by hills and river valleys, not primarily by a narrow sea channel. Bangladesh shares a long land boundary with India around its western, northern, and eastern sides. Pakistan lies across the Thar Desert and plains to the northwest of India. None of these are separated solely by the Palk Strait and Gulf of Mannar.

Common Pitfalls:
Confusion can arise if a learner mixes up different straits, such as Palk Strait, Malacca Strait, and Hormuz Strait. Another error is to focus on general neighbours of India and ignore the mention of specific water bodies in the question. Always link Palk Strait and Gulf of Mannar specifically with the maritime boundary between India and Sri Lanka.

Final Answer:
The country separated from mainland India by the Palk Strait and the Gulf of Mannar is Sri Lanka.