In the idiom question, choose the option that best expresses the meaning of the phrase "couch potato".

Introduction / Context:
Idioms are expressions whose meanings cannot always be guessed from the literal meanings of their individual words. The expression couch potato is a humorous idiom in modern English. To answer correctly, we must know how this expression is used in everyday language and media.

Given Data / Assumptions:

The idiom given is couch potato.

The options describe different types of people and behaviours.

The literal image is of a potato lying on a couch, suggesting inactivity.

We are asked for the best explanation of the idiom meaning.

We assume general conversational English usage.

Concept / Approach:
Couch potato refers to a person who spends many hours sitting or lying on a couch, usually watching television and doing very little physical activity. It implies laziness or a sedentary lifestyle. Among the given options, the one that most directly reflects this sense is a person who prefers to watch television. The other options mention friendliness, emotional calmness, traditional ideas or constant travel, none of which match the central idea.

Step-by-Step Solution:
Step 1: Recall that the idiom is frequently used to criticise someone who sits all day in front of a television. Step 2: Examine option B, a person who prefers to watch television. This matches the image of someone who spends much time on the couch. Step 3: Examine option A, an old person who has oldfashioned ideas. This describes a conservative person but says nothing about their level of physical activity. Step 4: Examine option C, a person who does not seem very friendly. This has no connection to couches or television. Step 5: Examine option D, someone who stays calm and does not show their emotions, which refers to emotional control, again unrelated to the idiom. Step 6: Examine option E, a person who travels constantly for work. This would describe an active person who moves a lot, almost the opposite image.

Verification / Alternative check:
Consider common usage: advertisements and news reports often talk about reducing couch potato habits and encouraging exercise, clearly associating the phrase with inactivity and television watching. The idea of a vegetable like a potato lying motionless on a sofa reinforces the association with physical laziness. None of the other options mention inactivity or television, confirming that only option B fits.

Why Other Options Are Wrong:
Option A misdirects attention to age and beliefs rather than lifestyle. Option C describes a social trait of being unfriendly, not a habit of sitting and watching television. Option D focuses on emotional control, which is completely different from the idea of passively watching television. Option E depicts someone who travels for work and is therefore not a couch potato.

Common Pitfalls:
Some learners overthink idioms and try to create complex meanings instead of remembering the simple, common image. In this case, remembering that couch potato appears in health campaigns about reducing screen time makes the meaning easy to recall. Visualising the literal image also helps.

Final Answer:
The idiom couch potato means a person who prefers to watch television, usually in a very inactive way.