In the United States, Payments to Labor Account For

In the United States, payments to labor account for:

A) 70% of total income, a share that has not fluctuated much in the past 30 years.
B) 50% of total income, but the returns to land have been increasing.
C) only 30% of total income, and this number is falling.
D) 90% of income and can be broken down into human capital and physical capital.