Answer:
The answer is "Option D".
Explanation:
Trojan program is a malicious code that is also known as a virus. It is a rootkit, that aims to infect the computer to hide or obscure an object. These programs are mainly used to download additional content, such as additional pieces of malware, to the infected computer, and other options are wrong that can be defined as follows:
- In option A, It is not correct, this option infects the system.
- In option B, It is used for infects another computer that's why it is incorrect.
- In option C, It is incorrect because it is used in cybersecurity.