Final answer:
The concurrent or shared power is the power to regulate interstate commerce.
Step-by-step explanation:
In the context of the question, the concurrent or shared power is the power to regulate interstate commerce (option b).
Under the U.S. Constitution, the power to regulate trade within the state (option a) is considered a reserved power of the states, while the power to license occupational specialties (option c) is typically a state power as well. Additionally, the power to provide for the general welfare of citizens (option d) is a broad power that can be exercised by both the state and federal governments.
Concurrent powers are powers that are shared between the national government and state governments. One of the key examples of a concurrent power is the power to regulate interstate commerce. This power allows the federal government to regulate trade and business activities that occur between states, ensuring fair and consistent regulations for businesses and consumers across state lines.