Answer:
D. online reference
Explanation:
An "online reference" refers to a digital reference that end users may utilize for their work or other daily activities. For example, if a person is looking for the synonym of a particular word, she may then refer to the thesaurus.
A blog is a website where you can find personal journals from different writers.
An e-book is an "electronic book." This allows people to read book digitally.
An e-zine is an "electronic magazine." This is a magazine in its digital form.
