Find the erroneous segment; if none, select ‘‘No error.’’ Sentence: We must go and congratulate him for his brilliant performance.

Introduction / Context:
English has fixed prepositional patterns with certain verbs. With ‘‘congratulate,’’ the standard preposition introducing the reason is ‘‘on,’’ not ‘‘for,’’ in formal usage.

Given Data / Assumptions:

• Verb: ‘‘congratulate’’
• Current preposition: ‘‘for’’
• Complement: ‘‘his brilliant performance’’

Concept / Approach:
The idiomatic frame is ‘‘congratulate someone on something’’ (e.g., ‘‘congratulate her on her success’’). While ‘‘for’’ can occur in informal speech, tests of standard usage consider ‘‘on’’ the correct choice.

Step-by-Step Solution:
Swap preposition: ‘‘for’’ → ‘‘on.’’Keep modality and coordination: ‘‘We must go and congratulate …’’ is fine.Correct sentence: ‘‘We must go and congratulate him on his brilliant performance.’’

Verification / Alternative check:
Compare with similar verbs: ‘‘commend someone on/for’’ exists with both options, but ‘‘congratulate’’ overwhelmingly takes ‘‘on’’ in careful writing.

Why Other Options Are Wrong:
A, C, and D are fine; the lexical-prepositional error is isolated in B.

Common Pitfalls:
Overgeneralising ‘‘for’’ to mark reason after all verbs. Memorise common verb–preposition pairs: ‘‘apologise for,’’ ‘‘thank for,’’ ‘‘congratulate on.’’

Final Answer:
and congratulate him for