How did the Laissez faire contribute to the Great Depression

In the wake of the great the great depression in the early 20th century lasissez-faire yielded to keynesian ecomnics named for its originator the british economist john maynard keynes which held that government could relieve unemployment and increase economic activity through appropriate tax policies and public expenditures

c is the correct 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)