Suppose the U.S. House of Representatives is debating a bill to fund construction and maintenance for the nation’s highway system. Representative Sandy Shady adds a provision to the bill that would fund a new public art museum in her district. The authorization of expenditure for the museum would be an example of

(A) an earmark.
(B) an unfunded liability.
(C) a collective action problem.
(D) a principal-agent problem.