The inspector of excise has to conduct regular checks and . . . . . . . to visit the unit at least once a day.

is required
requires
is requiring
required

The correct answer is: A. is required

The inspector of excise has to conduct regular checks and is required to visit the unit at least once a day.

The verb “to require” means to have a need or obligation for something. In this case, the inspector of excise has a need or obligation to conduct regular checks and to visit the unit at least once a day.

The other options are incorrect because they do not express the same meaning as “to require.”

  • Option B, “requires,” is the present tense form of the verb “to require.” However, the sentence is in the passive voice, so the correct verb form should be the past participle “required.”
  • Option C, “is requiring,” is the present progressive form of the verb “to require.” However, the sentence is not about a current action, but about a general obligation.
  • Option D, “required,” is the past tense form of the verb “to require.” However, the sentence is not about a past action, but about a general obligation.