How does the federal government determine the level of income that constitutes the poverty line for a family of a particular size?

a. The U.S. government defines the poverty line as income at or below three times the amount of money needed to buy basic, nutritionally sufficient food for all family members.
b. The U.S. government defines the poverty line as income at or below four times the amount of money needed to buy basic, nutritionally sufficient food for all family members.
c. The U.S. government defines the poverty line as income at or below twice the amount of money needed to buy basic, nutritionally sufficient food for all family members.
d. The U.S. government defines the poverty line as income at or below five times the amount of money needed to buy basic, nutritionally sufficient food for all family members.

a