Assertion:  In the 1970s, the phrases such as redistribution with growth and growth and equity were incorporated into the definition of development.
Reasoning: In the post-World War II era, the concept of development was synonymous with economic growth. But, later even the countries having high economic growth, experienced a speedy rise in poverty because of its unequal distribution.

Both Assertion (A) and reasoning (R) are correct, and R is the correct explanation of A.

Hence, development is a multi-dimensional concept and signifies the positive, irreversible transformation of the economy, society and environment. The concept of development is dynamic and has evolved during the second half of the twentieth century. In the post-World War II era, the concept of development was synonymous with economic growth which is measured in terms of a temporal increase in the gross national product (GNP) and per capita income/per capita consumption. But, even the countries having high economic growth, experienced a speedy rise in poverty because of its unequal distribution. So, in the 1970s, the phrases such as redistribution with growth and growth and equity were incorporated into the definition of development. While dealing with the questions related to redistribution and equity, it was realised that the concept of development cannot be restricted to the economic sphere alone.