What Best Describes Unemployment Spells in the United States

What best describes unemployment spells in the United States?

A) Most spells of unemployment are rather short, and therefore most weeks of unemployment can be attributed to these short spells.
B) Most spells of unemployment are rather short, but most weeks of unemployment are attributed to very long spells.
C) Most spells of unemployment are rather long, and therefore most weeks of unemployment can be attributed to these long spells.
D) Most spells of unemployment are rather long, but most weeks of unemployment are attributed to short spells.
E) Most spells of structural unemployment are much shorter than most spells associated with frictional unemployment, but how these two interact to determine the average length of an unemployment spell is unknown.