What is the term used for unsolicited e-mail?

The correct answer is E. Spam.

Spam is unsolicited, unwanted, and often harmful email sent to a large number of recipients for the purpose of advertising, phishing, spreading malware, etc. It is a major problem on the Internet, and can be very annoying and disruptive.

News group is a discussion forum on the Internet where people can post messages and read messages posted by others. Usenet is a network of newsgroups. Backbone is the main network that connects other networks together. Flaming is a type of online communication that is characterized by angry or aggressive language.

I hope this helps!