Older Hispanics and African Americans Had Irregular Patterns of Work

Older Hispanics and African Americans had irregular patterns of work because:

A) they primarily worked in high-skilled jobs where they were subject to high mental and physical stress.
B) they had higher mortality rates than any other ethnic minority in the United States.
C) they typically worked in sectors of the labor force where layoffs are common or work is seasonal.
D) Native Indians were the preferred labor force over these groups.