Error Spotting – Identify the part of the sentence that contains a grammatical error (choose exactly one; select “No error” if the sentence is fully correct). Sentence: A) Mohan has collected B) all the necessary documents C) and have written a good paper D) for this conference.

Introduction:
This item tests subject-verb agreement across coordinated verb phrases sharing the same singular subject.

Given Data / Assumptions:

• Subject: "Mohan" (singular).
• Perfect tense auxiliary in first verb phrase: "has collected."
• Second verb phrase mistakenly uses "have written."

Concept / Approach:
When two verb phrases share a single subject, agreement must be consistent. With a singular subject in present perfect, use "has" for both: "has collected" and "has written."

Step-by-Step Solution:
1) Identify subject: "Mohan."2) First auxiliary: "has" → correct for singular.3) Second auxiliary must match: change "have written" to "has written."4) Correct sentence: "Mohan has collected all the necessary documents and has written a good paper for this conference."

Verification / Alternative check:
Reduce the sentence: "Mohan has collected and has written." Both must align with singular subject, confirming the fix.

Why Other Options Are Wrong:

• A, B, D: Grammatically sound as parts of the corrected sentence.

Common Pitfalls:
Letting the auxiliary agree with the nearest noun instead of the true subject; dropping a repeated auxiliary incorrectly.

Final Answer:
Option C