Why are retroviruses considered a special class of viruses?

hello

answer: collecting information/data

reason: the student is going around and asking people questions to collect data

i hope this

b is the answer and if you need further with anything message me

i took a test for bio that had this question and these were the correct answers, not sure if this is any now lol

the nervous system and the muscular system work together.  

sweat reaches the surface of the skin and evaporates into the air.

muscles underneath the skin relax, causing hair on the skin to lay flat.