Which of the following best describes the principle of concurrent powers in the American federal system?

The correct answer to the question "Which of the following best describes the principle of concurrent powers in the American federal system?" is Option B: Powers shared by both the national and state governments..

The other options — A) Powers exclusively reserved to the national government., C) Powers exclusively reserved to the state governments., D) Powers implied by the Necessary and Proper Clause. — are incorrect for this CLEP Exam Prep question. As explained above: Concurrent powers are those exercised independently by both the federal government and state governments, such as taxing, building roads, and establishing courts.