Final answer:
In the 2012 budget, national defense and Social Security were the two categories with the most spending, being major components of the federal budget.
Step-by-step explanation:
According to the 2012 budget, the two functions that received the most spending were B. national defense and D. Social Security. These categories, along with healthcare and interest payments, accounted for a significant portion of the federal budget. National defense spending is associated with military operations and maintaining the armed forces, while Social Security is a program that provides financial support to retired workers, disabled individuals, and survivors of deceased workers.
The remaining categories of federal government spending, including international affairs, transportation, and income security, accounted for the remaining percentage.