Correct Answer:
B. The laborers have been on strike for four days
The correct option is B. The laborers have been on strike for four days. This sentence correctly uses the present perfect continuous tense ('have been on strike') to describe an action that started in the past (four days ago) and is still continuing in the present. The preposition 'on' is also correct for 'on strike'.
- A. The laborers are on strike for four days: The present simple 'are on strike' is incorrect when a duration ('for four days') is specified, as it implies a current state without indicating its ongoing nature from the past.
- C. The laborers are being on strike for four days: The present continuous passive 'are being on strike' is grammatically incorrect and not used in this context.
- D. The laborers have been in strike for four days: The preposition 'in' is incorrect; the correct idiom is 'on strike'.