We Would Expect a Macroeconomist, as Opposed to a Microeconomist

We would expect a macroeconomist, as opposed to a microeconomist, to be particularly interested in

A) explaining how economic changes affect prices of particular goods.
B) devising policies to deal with market failures such as externalities and market power.
C) devising policies to promote low inflation.
D) identifying those markets that are competitive and those that are not competitive.