___________ is referred as a program that is put in someone's computer to secretly gather information about the user and spread it.

Correct option is A

Spyware is a type of malware that secretly collects user data without their consent.

• (b) Dropbox is a cloud storage service, not malware.

• (c) Worm is a type of malware that self-replicates and spreads, but its main purpose is not data collection.

• (d) Payload refers to the harmful part of malware but is not a type of malware itself.