Choose the option that best completes the gap(s) The new national security committee ____ retired military personnel.

The correct option to complete the sentence is: comprises.

Here's the explanation:

• The word "comprises" is used correctly when the subject of a sentence includes or consists of certain elements. The basic structure is: "A comprises B." In this case, "The new national security committee comprises retired military personnel."
• The word "comprised" is the past tense of "comprise," and it would indicate a past situation. Since there is no indication that the sentence is referring to the past, "comprises" is more appropriate.
• The option "comprises of" is incorrect because when you use "comprise," you do not follow it with "of." The phrase "comprises of" is not grammatically correct.
• The phrase "is comprising" is also incorrect because "comprise" is typically not used in a progressive tense. The verb "comprise" usually follows the pattern of present tense (comprises) or is used in simple past (comprised) without the auxiliary "is."