Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the right order to form a meaningful and coherent paragraph.

(A) Necessity is indeed the mother of invention. 
(B) Why?
(C) Because Chewang Norphel, a retired civil engineer in the Jammu and Kashmir government came up with the idea of artificial glaciers.
(D) When areas in and around Leh began to experience water shortages, life didn’t grind to a halt.