Final answer:
The correct answer, which is an example of Congress acting on an implied power, is not provided in the listed options. Implied powers are those that are not explicitly written in the Constitution but deemed necessary for executing governmental duties.
Step-by-step explanation:
The question is asking which of the listed options reflects Congress acting on an implied power in the Constitution. An implied power means it is not explicitly written in the Constitution but is considered necessary to execute the duties of Congress.
- a) Passing a law regulating interstate commerce is an enumerated power of Congress as found in the Commerce Clause of the Constitution.
- b) Approving a constitutional amendment is an explicit constitutional power of Congress.
- c) Declaring war on another country is also an enumerated power, specifically listed in the Constitution.
- d) Ratifying a state law is not a power of Congress.
From the information provided and other knowledge on the subject, the correct answer is not listed among these options. However, an example of an implied power would be the power to regulate the sale of tobacco in the states because it can be considered necessary for Congress to legislate for public health under the commerce clause, although it is not explicitly stated in the Constitution.