Which physical part of India is made of young fold mountains?

Correct answer: Himalayas

The direct answer is option C, the Himalayas. Young fold mountains form when tectonic plates push against each other and layers of rock are folded upward. The Himalayas formed from the collision of the Indian Plate with the Eurasian Plate and are geologically young, still rising in a tectonically active region. Option C is correct because the Himalayas are India's well-known young fold mountain system. Option A, the Peninsular Plateau, is an ancient, stable block of very old rocks, not a young folded mountain chain. Option B, the Thar Desert, is a dry sandy region and does not represent young fold mountains. Option D, the Coastal Plains, are relatively low plains along the sea and are not a folded mountain system. The step-by-step identification is: look for a high mountain range, then ask whether it is young and folded; in India, that answer is the Himalayas. A useful contrast is young, high, rugged Himalayas versus old, worn-down ranges such as the Aravallis.