In the following idiom question, choose the option that best expresses the meaning of the idiom or phrase:\n\n"Go for a song."

Introduction / Context:
This question tests your knowledge of the idiomatic phrase go for a song. Idioms are fixed expressions whose meanings are not obvious from the individual words. Go for a song is a common phrase in English related to prices and buying or selling. To answer correctly, you must know how this idiom is used in everyday language, especially in relation to bargains.

Given Data / Assumptions:

• Target idiom: go for a song.
• Options: a persons favourite music, happy go lucky attitude, sold cheaply, something which is prohibitively expensive.
• We assume a context like a car or a house going for a song.

Concept / Approach:
Go for a song means to be sold at a very low price, much cheaper than the real value. The image is that you could almost pay only a song for it, instead of real money. It is therefore associated with bargains and cheap purchases. The other options relate either to personal taste in music, a carefree attitude, or very high cost, none of which match the idiom's actual meaning.

Step-by-Step Solution:
Step 1: Recall the standard usage: The old house went for a song means it was sold very cheaply. Step 2: Identify which option refers to being sold at a low price. Step 3: Recognise that Sold cheaply is the only option that fits this meaning. Step 4: Select Sold cheaply as the correct interpretation of the idiom.

Verification / Alternative check:
Use the idiom in sentences similar to common usage. For example, The car went for a song at the auction means the car was sold for a very low price. If you try to replace the idiom with any of the other options, such as The car was a persons favourite music or The car had a happy go lucky attitude, the sentence becomes absurd. Only the idea of a low price preserves the meaning.

Why Other Options Are Wrong:
Option A, A persons favourite music, relates to the songs someone likes but does not reflect pricing. Option B, Happy go lucky attitude, describes a carefree personality and has nothing to do with selling or buying. Option D, Something which is prohibitively expensive, is the direct opposite of the idiom, because go for a song implies cheapness, not high cost. These are all distractors.

Common Pitfalls:
Learners sometimes interpret idioms literally and think go for a song must be related to music. Others may overthink and choose the most complicated option. Remember that idioms have established meanings in real usage, and you should rely on those rather than guessing from the words alone. Reading widely and noting idiomatic expressions in context is the best way to master them.

Final Answer:
The idiom go for a song means sold cheaply.