Answer:
D. is concerned with the expansion and contraction of the overall economy.
Explanation:
Macroeconomics -
It is the sub branch of the economics , which deals with the economy as a whole complete unit , is referred to as macroeconomics .
The study includes the factors like deflation , inflation , national income , rate of economic growth , gross domestic product etc.
It includes the global economy , national as well as regional economy .
The study helps to deal with problems of economy , evaluation of any economic policies .
Hence , from the given question ,
The correct option is D.