Question

Why is it best to run av scans when the computer isn���t being utilized?

Answer 1

A and B I'd say :)
Scan slows the computer while you are using it.
A few process are also unscannable whrn you use it (I may be wrong on this)

Answer 2

Answer:

A. the scan consumes  resources and can impede computer performance.

Explanation:

An AV(Antivirus) scan is run to identify and clean viruses from the system.

When doing this, the antivirus software goes through all the processes and files on the system disk(s). This scanning is a computationally intensive process as it checks the CPU, the memory and disk time from applications on the system. This obviously consumes a whole lot of resources and might reduce computer performance especially the computer is utilized for other processes at the same time.