Correct option is B
A
vaccine is another term sometimes used for antivirus software. It refers to software designed to detect, prevent, and remove viruses and other malicious software from computers. The term "vaccine" metaphorically implies protection and prevention, similar to how vaccines work in medicine.
Worm: A type of malware that replicates itself to spread to other computers.
Trojan horse: Malware disguised as legitimate software to gain unauthorized access.
DES (Data Encryption Standard): An encryption algorithm used for securing data, not related to antivirus.
Therefore, the correct answer is (b) Vaccine.
