Final answer:
The Reagan administration's secret plan to fund the Contras in Nicaragua was motivated by the Boland Amendment, which had banned the U.S. from providing aid to the Contras.
Step-by-step explanation:
The Reagan administration's secret plan for funding the Contras in Nicaragua was primarily motivated by the Boland Amendment. Passed by Congress in 1982, the Boland Amendment prohibited the U.S. from aiding the Contras, a group opposed to the Sandinista government. However, the Reagan administration sought to continue this support covertly, going so far as to use proceeds from secret arms sales to Iran as a means of circumventing the restrictions imposed by the Boland Amendment. The secret funding of the Contras was part of the administration's broader effort to limit Soviet influence in Central America and support anti-Communist forces, despite the amendment's attempts to halt such aid.