The correct answer is (D) 1. Something that is added to, or is extra to, another, but which is subordinate to it. 2. An assistant or person who is joined to another in some service. 3. A modifying word or phrase.

Examples of use:

• The adjunct in this sentence is at the end on the same line.
  
  
• The elderly gentlemen is an adjunct professor at the local university.