Correct Answer:
D. A lazy person
The idiom "a couch potato" refers to a person who spends a great deal of time sitting or lying on a couch, typically watching television, and engaging in little to no physical activity. Therefore, the correct option is D: A lazy person.
- A: A clever person, B: An important person, and C: An ideal person are incorrect because the idiom specifically denotes idleness and lack of productivity, not intelligence, significance, or perfection. The term highlights a sedentary lifestyle, often associated with laziness and inactivity.