Which of the following are true with respect to fold mountains?
1. Their tops are often buried beneath snow and ice.
2. They form rugged peaks. 3. They are caused by contraction of the earth’s crust.
4. They contain a core composed of metamorphic and igneous rocks.
(a) 1, 3 and 4 (b) 2, 3 and 4 (c) 1 and 2 (d) 1 and 4