For this question, you are presented with a short paragraph in which four words are underlined, one of which is a grammar or spelling error.

When officer F arrived to supervise inmate visits, the visitation area was very crowded. The sergeant on duty informed him that the morning staff had admitted several visitors on the incorrect visiting day He reminded Officer F that any visitors arriving on the incorrect day should be turned away After the sergeant left two new visitors arrived wanting to visit his son. Officer F explained to the visitors that they can only visit on their assigned visiting day The visitors explained they had come from out of state and were unaware of the rules. Officer $F$ apologized for the inconventence and informed them they would have to return on their son's regular visiting day, which upset them They demanded to see the supervisor to express their grievance.

Based ONLY on the paragraph above which one of the underlined words contains a grammar orspelling error?

A$.$ He

B$.$ them

c$.$ his

D$.$ their