Answer:
is concerned with the expansion of a small business into a large corporation
Macroeconomics is the study of the economy as a whole. It studies aggregate variables: economic variables like employment or inflation, but in a large scale.
Because large corporations tend to have a big effect on the overall economy of the regions where they operate, macroeconomics is naturally concerned with them.
Is concerned with the expansion and contraction of the overall economy.
Macroeconomics, as the study of the economy as a whole, is concerned with how the overall economy behaves in time.