Identify the part of the sentence that contains an error in "At the party Rohit introduced me to his friend who is radio jockey."

Introduction / Context:
Error spotting questions are designed to test your grasp of basic English grammar, especially articles, prepositions, verb forms, and sentence structure. In this sentence, you must identify which underlined part contains a grammatical mistake. The sentence talks about Rohit introducing the speaker to his friend at a party.

Given Data / Assumptions:
The sentence is divided into four parts:

• (A) At the party
• (B) Rohit introduced me to his friend
• (C) who is radio jockey.
• (D) No error

You must find which part is incorrect or choose D if there is no error.

Concept / Approach:
The main grammar point here involves the use of articles (a, an, the) before singular countable nouns. Professions or designations usually require an article before them, for example "She is a teacher", "He is an engineer". The rest of the sentence structure appears standard and natural.

Step-by-Step Solution:
Step 1: Examine part A: "At the party". This phrase correctly uses the article "the" and a preposition; it is grammatically fine. Step 2: Check part B: "Rohit introduced me to his friend". This is also correct: subject "Rohit", verb "introduced", indirect object "me", and object "his friend". Step 3: Look at part C: "who is radio jockey." The phrase describes the friend's profession. Standard English requires an article before a singular countable noun like "radio jockey". It should be "who is a radio jockey." Step 4: Therefore, the error lies in part C due to the missing article "a".

Verification / Alternative check:
Read the corrected full sentence: "At the party Rohit introduced me to his friend who is a radio jockey." This sounds natural and grammatically correct. If any other part had a serious error, the sentence would still feel wrong even after fixing part C, but that does not happen here. Parts A and B remain appropriate in grammar and meaning.

Why Other Options Are Wrong:

• Option A: "At the party" is a correct prepositional phrase of time and place.
• Option B: "Rohit introduced me to his friend" has a correct verb and object structure.
• Option D: Cannot be chosen because we have already identified a clear error in part C.

Common Pitfalls:
Many students ignore article usage with professions and designations, especially in spoken English where people sometimes drop small words. Competitive exams, however, follow standard written grammar and expect forms like "a doctor", "an engineer", "a radio jockey". Make it a habit to mentally insert an article every time you see a singular countable noun used as a complement after "is" or "was".

Final Answer:
The error is in part C, because it should read "who is a radio jockey".