Under which of the following scenarios would it be appropriate for the vice president to assume the office of the president?
a. president obama travels to nova scotia to vacation with his family.
b. president obama must resign amid charges of fraud and tax evasion.
c. president obama falls ill to chronic pneumonia and must cancel his diplomatic trip to turkey, sending vice president biden instead.
d. president obama must attend to his reelection campaign trail, requiring him to give speeches across the country, leaving vice president biden to attend to the president’s duties.

I did the quiz, and it's letter B.

B. President Obama must resign amid charges of fraud and tax evasion.

Explanation:

According to Article II, Section 4 of the United States Constitution, the President, Vice President and all civil officers of the nation, is to be removed from office if they are impeached or convicted of committing treason, bribery, or other high crimes and misdemeanors. Besides, the 25th Amendment also states that whenever the President is removed from office, whichever reason it may be, the Vice President ought to assume the office of the President.

Therefore, if "President Obama" had charge of fraud and tax evasion, that would be enough reason to remove him from office. And, as the 25th Amendment claims, it is the Vice President's duty to become President.