Which of the following is an example of a delegated power?

The power to regulate interstate commerce is a clear example of a delegated power because it is specifically granted to the federal government by the Constitution. Delegated powers, also known as enumerated powers, are those powers explicitly listed in the Constitution, and the regulation of interstate commerce falls under the federal government's authority to manage trade and economic activities that cross state lines.

This power is significant as it allows the federal government to create a uniform economic policy that facilitates trade between states, thus contributing to a cohesive national economy. It also prevents states from enacting conflicting regulations that could hinder trade and commerce on a broader scale. In essence, interstate commerce is a vital aspect of the national economy, and its regulation is essential for maintaining economic stability and efficiency.

In contrast, the other choices represent powers that are typically reserved for state governments or are not explicitly delegated to the federal government by the Constitution. Local government setup, educational systems, and marriage laws are primarily managed at the state level, reflecting the principles of federalism that allocate certain powers to states to govern their own affairs.