Mark the part with an error; if none, choose ‘‘No error.’’ Sentence: Had I come to know about his difficulties would have certainly helped.

Introduction / Context:
This question checks conditional inversion and the necessity of an explicit subject in the main clause.

Given Data / Assumptions:

• The sentence is a third-conditional type expressing a counterfactual past condition.
• Inverted conditional ‘‘Had I come…’’ is acceptable for ‘‘If I had come…’’
• The main clause must include the subject ‘‘I’’.

Concept / Approach:
Conditionals with inversion drop ‘‘if’’ and invert auxiliary + subject in the condition clause only. The result clause remains uninverted and must contain a subject.

Step-by-Step Solution:
Condition clause: ‘‘Had I come to know…’’ = correct inversion.Result clause supplied: ‘‘would have certainly helped’’ (missing subject).Correct form: ‘‘…I would have certainly helped.’’

Verification / Alternative check:
Restore ‘‘if’’: ‘‘If I had come to know…, I would have certainly helped.’’ Both clauses now look complete.

Why Other Options Are Wrong:

• A–C: Grammatically fine; problem lies in the main clause.

Common Pitfalls:
Omitting the pronoun in the main clause after using an inverted if-clause.

Final Answer:
would have certainly helped.