Identify the segment in the sentence which contains a grammatical error. You are fond of instrumental music, isn't it?

Option 4 : isn't it

The erroneous segment is "isn't it"

• The given sentence is an example of a tag question.
• In a tag question, a positive affirmation is followed by a negative question and vice versa.
• We use the same auxiliary verb in question that we have used in the main sentence.
• In the given sentence, we started with 'You are' in the main sentence so the tag question will be' aren't you?'
  • Example: You are good at singing, aren't you?

The correct sentence is: You are fond of instrumental music, aren't you?

Hence, the correct answer is option 4.