Reverse transcriptase is an enzyme utilized by many retroviruses. This enzyme most likely demonstrates which type of activity

The activity of speed up the process.

Explanation:

Reverse transcriptase is an enzyme encoded from the genetic material of retroviruses that accelerate or speed up the process of  transcription of retrovirus ribonucleic acid into deoxyribonucleic acid. Reverse transcriptase enzyme is also called RNA-directed DNA polymerase. Some retroviruses such as human immunodeficiency virus (HIV) and avian myeloblastosis virus used this Reverse transcriptase enzyme.

b.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.