Final answer:
The member of President Trump's cabinet listed is Rex Tillerson, who was the Secretary of State. Other options were part of previous administrations. Cabinet members are appointed by the President and play a significant role in national policy and governance.
Step-by-step explanation:
The question pertains to identifying a member of the cabinet during President Donald Trump's administration. The correct answer from the options provided is A) Rex Tillerson, who served as the Secretary of State from February 1, 2017, to March 31, 2018. As Secretary of State, Tillerson was responsible for foreign policy and was fourth in line to the presidency.
The other individuals listed were not part of President Trump's cabinet. John Kerry served as Secretary of State under President Barack Obama, Eric Holder served as Attorney General also under President Obama, and Janet Napolitano served as Secretary of Homeland Security under President Obama. Understanding the composition of the executive branch and its cabinet members is an important aspect of recognizing the structure and functions of the United States government.
Cabinet members play a crucial role in advising the President on various matters within their respective departments. The President appoints members to these positions, and the appointments must be confirmed by the Senate. The importance of the cabinet lies in the expertise the members bring to the administration, helping in the formulation and execution of national policies.