What is the main purpose of taxation?
a-to promote economic equality among citizens
b-to pay for government programs and operations
c-to build up a reserve money supply and reduce debt
d-to stimulate the economy and encourage spending

The main purpose of taxation is B. TO PAY FOR GOVERNMENT PROGRAMS AND OPERATIONS.

Taxation is levied by the government. Tax is a required payment to local, state, or national government. It is the primary source of income by the government.

Taxes are used to fund public goods and services. It is imposed to influence behavior, to stabilize the economy, and to redistribute income. 

The congress completes the diagram

The freedmens bureau   disturbing supplies