Atrojan horse:

a) is malware named for a breed of fast-moving near-eastern horses.
b) is a virus that replicates quickly.
c) installs spyware on users' computers.
d) is software that appears to be benign but does something other than expected.
e) is a type of sniffer used to infiltrate corporate networks.

The answer is "option D"

Explanation:

Trojan horse is a software, that is installed on a system and appears benign, but in actual it is the addition of malicious which unexpected modifications in config files and unusual activity even when the computer is idle are strong signs that a Trojan exists on a system. and other options are not correct that can be described as follows: