No offence intended _______ I think you haven't understood the problem correctly.A.whenB.asC.butD.if

To fill in the blank in the sentence "No offence intended _______ I think you haven't understood the problem correctly," we need to choose a conjunction that logically connects the two clauses.

Analyzing the Options

1. A. when - This option implies a timing or condition, which does not fit well in the context of the sentence.
2. B. as - This suggests a simultaneous occurrence, but does not convey the intended contradiction.
3. C. but - This conjunction introduces a contrast between the two statements, making it appropriate for expressing the speaker’s intent to clarify misunderstanding after stating no offense.
4. D. if - This word implies a condition that does not logically connect with the speaker's assertion regarding the misunderstanding.

Conclusion

The most logical connector for the sentence is C. but. The completed sentence reads: "No offence intended, but I think you haven't understood the problem correctly."

Final Answer

C. but