Which of the Following Statements Most Likely Lies Within the Realm

Which of the following statements most likely lies within the realm of macroeconomics?

A) An increase in the price of automobiles will lead to a decrease in the quantity of automobiles demanded.
B) Due to process innovations in computer chip manufacturing, the market supply of computers increased.
C) Due to an economic recession, manufacturing firms began implementing layoffs of their workforces.
D) Anticipating that the benefits would outweigh costs involved, an undergraduate student purchases the course textbook.
E) A consumer electronics firm found that it could minimize its losses by shutting down its operations altogether.