Why Have Some Institutions Such as the World Bank Moved

Why have some institutions such as the World Bank moved away from using GNP as a measure of a country's financial status and toward an adjusted GNP based on purchasing power parity (PPP) ?

A) They believe that PPP is a more accurate measure because it takes into account the cost of locally produced and consumed goods.
B) They believe that PPP is a more accurate measure because it takes into account the social costs of neoimperialism.
C) They believe that PPP is a more accurate measure because it separates the North and South before making comparisons.
D) They believe that PPP is a more accurate measure because it places newly industrializing countries into its own category.