Who served as the President of the United States alongside Vice President Mike Pence?

The correct answer is based on the fact that Donald Trump was the President of the United States from January 20, 2017, to January 20, 2021, with Mike Pence serving as his Vice President during that entire term. This particular pairing marked a significant period in U.S. political history, characterized by distinct policies and actions in both domestic and foreign affairs.

The leaders mentioned in the other options served during different timeframes. Barack Obama was President from January 20, 2009, to January 20, 2017, preceding Trump's term. George W. Bush held the presidency from January 20, 2001, to January 20, 2009, which means he was in office long before Trump. Joe Biden succeeded Trump, taking office on January 20, 2021, so he did not serve alongside Pence. Thus, the historical context of Trump and Pence's administration uniquely identifies them as the correct answer.