The correct answer is D) enforcing laws.
The option that best describes a role of the executive branch of the federal government is "enforcing laws."
In the United States, the executive branch is responsible to enforce laws in all the territory. The figure that represents the executive branch is the US President, who is also the Commander-in-chief of the Armed Forces and the Head of the State. He also is the leader of the Cabinet, and he appoints the members of the different departments in his cabinet.
The other options of the question were A) governing commerce. B) interpreting laws. C) regulating taxes.