Why Is a Per Capita Measure Used as the Basis

Why is a per capita measure used as the basis for a nation's economic growth rate?

A) Per capita measures focus on capital, which is the most important factor in growth.
B) This is an adjustment for the cost of living, so the measure captures growth of output rather than price.
C) Adjusting for the size of the population allows focus on the average person's situation.
D) Per capita adjustments give insights into the gap between the most and least prosperous people in a country.