Select the most appropriate option to substitute the underlined segment in the given sentence. If there is no need to substitute it, select ‘No substitution required’.

All the buses leaving between 10 p.m. and 5 a.m. has been cancelled.

The correct answer is 'were cancelled'.

Key Points

• In this sentence, the subject is 'All the buses'.
• Since it's a plural subject, we should use 'have' instead of 'has'.
• However, the sentence is referring to a past event - the cancellation of the buses.
• Therefore, instead of using a present tense verb, we should be using a past tense verb.
• The correct past tense conjugation in this case is 'were cancelled'.
• Thus, the corrected sentence should read "All the buses leaving between 10 p.m. and 5 a.m. were cancelled."

Hence, the correct answer is "Option 3". 

Additional Information

• were been cancelled:
  • This option isn't correct because 'were been' is grammatically incorrect in English.
  • It's not a proper use of verb tenses.
• being cancelled:
  • This choice uses the passive continuous form which isn't accurate for a completed past action.
  • The 'being' form should be used for ongoing actions in the past, which wouldn't be appropriate as the sentence refers to a completed action.