Identify the segment of the sentence, which contains the grammatical error, If there is no error mark "No Error".

No sooner did the (A)/ comedian begin his act (B)/ when the audience roared with laughter. (C)/ No error (D)

The correct answer is option 3 i.e. C

Explanation:

• Some conjunctions such as: '; No sooner...than', 'Hardly/scarcely...when', are used in a pair. No sooner............ than is coordinating conjunction and both occur together. 
• For example :
  • Hardly had I left the cinema hall than I saw the actor himself.  
  • Hardly had I left the cinema hall when I saw the actor himself.   ​​
• Hence in the 3rd part of the sentence, 'than' will be used instead of 'when'.

• Whenever 'did' is used as an auxiliary/helping verb, the main verb will be in 1st form.
• In case of these conjunctions, an inverted form of the verb will be used as illustrated in the examples above.
  ​

Correct Sentence: No sooner did the comedian begin his act than the audience roared with laughter.