Final answer:
House Republicans' summons to Hillary Clinton in 2015 aimed at oversight of government processes while also taking on political undertones, reflecting the dual aspects of congressional hearings as tools for checks and balances and political strategy.
Step-by-step explanation:
When House Republicans summoned former Secretary of State Hillary Clinton to testify about Benghazi in 2015, they were exercising Congress's oversight power primarily to ensure that governmental procedures were implemented correctly, as per option (b), but the context suggests that there may have been additional political motives, including efforts to gain a political advantage or possibly impact Clinton's credibility in the face of her presidential campaign. These hearings are an example of Congress's role in foreign policy oversight and demonstrate the complex interplay of accountability, policy evaluation, and sometimes partisan politics. Committee hearings can be used as a tool to exercise the checks and balances prescribed by the Constitution, but they can also become arenas for political theater.