What official becomes president if the president and vice president died at the same time?

A. Chief Justice.
B. President pro tempore of the Senate.
C. Secretary of State.
D. Speaker of the House of Representatives.***

Right.

The correct answer is D. Speaker of the House of Representatives. In the event of both the president and vice president dying at the same time, the Speaker of the House of Representatives is next in line to assume the presidency. This is determined by the Presidential Succession Act of 1947. The act states that after the vice president, the speaker of the House is the next in line in the order of succession.

To confirm this, you can refer to the United States Constitution, Article II, Section 1, and the Presidential Succession Act of 1947. Additionally, you can also consult reputable sources such as government websites, political science textbooks, or legal references that explain the order of succession in case of a vacancy in the presidency.