General welfare of the public please help me

d is the best answer for this question.

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.