A combines the characteristics of computer viruses, worms, and other malicious codes with vulnerabilities found on public and private networks.

The answer is "Blended Threat"

Explanation:

In the given question some information is missing that is the option of the question, which can be described as follows:

a. Firewalls.

b. Mirror disc.  

c. Threat from the backdoor.

d. blended threat.  

It includes bugs malicious content like malware, grubs, and many other scripts. It helps in remembering things when you combine multiple tasks in a processor to help learn, Its combination of stuff is produced, and other choices were false that can be described as follows:

answer; i believe the correct answer is 50 pounds;

(because i need 20 chars)