The congressional budget office (cbo) is
a. legislative trade-offs typified by members exchanging votes for each other's bills
b. the official record of the proceedings and debates of the united states congress
c. an agency that audits the financial expenditures of the executive branch and federal agencies
d. a congressional support agency that evaluates the president's budget

The correct answer is D. The Congressional Budget Office is a congressional support agency that evaluates the president's budget.

Explanation:

The Congressional Budget Office is a US federal agency whose purpose is to provide US Congress with financial information, financial analysis, and reports to assist the Congress in deciding federal budgets and laws.  

On July 12, 1974, US 37th President Richard Nixon signed the Congressional Budget and Impoundment Control Act, which mentioned that an authority providing financial information and reports to Congress would be founded. On February 24, 1975, CBO was officially formed.

letter a is the answer