In the sentence Our departmental phone number has been changed, the complete subject is a. departmental phone number b. our departmental phone number C. our departmental phone d. phone number

The complete subject in the sentence "Our departmental phone number has been changed" is:<br /><br />b. our departmental phone number<br /><br />The complete subject includes all the words that tell who or what the sentence is about, which in this case is "our departmental phone number."