Answer:
C. Cloud-based
Explanation:
A software application is cloud-based if it allows users to access its features via the internet. Therefore going to the website url and clicking on a button to run a program that performs an action such as an anti-malware is a cloud-based delivery method. Cloud-based apps are a special case of web-based apps (or simply web apps).
PS: An application is host-based if it is run on the particular device (host) that needs it.