Question

What causes ‘u’ shaped valleys?
(A) River
(B) Rain
(C) Sea waves
(D) Glacier

Answer 1

Hint:Valley icy masses cut U-formed valleys, instead of the V-molded valleys cut by streams. During periods when Earth's atmosphere cools, ice sheets structure and start to stream downslope.

Complete answer:
Fjord, additionally spelled inlet, a long-restricted arm of the ocean, ordinarily reaching out far inland, that outcomes from the marine immersion of a glaciated valley. Numerous fjords are amazingly profound; Sognefjord in Norway is 1,308 m profound, and Canal Messier in Chile is 1,270 m.
The incredible profundity of these lowered valleys, expanding a huge number of feet beneath ocean level, is viable just with a cold beginning. It is expected that the huge, thick icy masses framed in these valleys were hefty to the point that they could dissolve the lower part of the valley far underneath ocean level before they drifted in the seawater. After the ice sheets liquefied, the waters of the ocean attacked the valleys.
Fjords normally are more profound in their center and upper compasses than at the offshore end. This outcome from the more noteworthy erosive intensity of the ice sheets nearer to their source, where they are moving most effectively and energetically. Given the relatively shallow edges of fjords, the bottoms of many have stale water and are wealthy in dark mud containing hydrogen sulfide.
Much of the time the valley, stunned with chilly trash, expands inland into the mountains; in some cases, a little icy mass remains at the valley's head. The waterway that shaped the first valley usually restores itself on the upper valley floor after the vanishing of the ice and starts to fabricate a delta at the fjord's head. Regularly this delta is the main put on the fjord where towns and homesteads can be set up.

Hence the correct answer is option (D).

Note:As ice sheets move through these valleys, they concentrate erosive activity over the whole valley, broadening its floor and over-steepening its dividers. After the icy mass retreats, it abandons a level lined, steep-walled U-formed valley.