Why Is It Critical to Download Authorized Updates for Computer

Multiple Choice

Why is it critical to download authorized updates for computer anti-virus software on a routine basis?

A) Occasionally, anti-virus software infects a computer with a virus even when it's trying to establish preventative care.
B) Computer viruses can spontaneously "pop up" in a system if the computer experiences multiple glitches in a short period of time.
C) User licenses for anti-virus software only last for short periods of time so that users must re-read the user agreements frequently to ensure they remain well informed.
D) Virus authors are constantly writing new viruses, and the anti-virus software definitions that identify a virus must similarly be written and updated constantly to remain effective.