Per Capita GDP in the US During the 20ᵗʰ Century

Per capita GDP in the US during the 20ᵗʰ century _____.

A) has remained about the same.
B) increased until about 1970 and decreased since then.
C) was cyclical,but generally trending upward throughout the century.
D) grew very quickly for the first half of the century and grew at a much lower rate in the second half of the century.