DOES ANYONE KNOW WHAT LOOP EMAIL IS?

Yes, An email loop is an infinite loop phenomenon, resulting from mail servers, scripts, or email clients that generate automatic replies or responses. If one such automatic response triggers another automatic response on the other side, an email loop is created.

  Was this for school?

If you have loop email in other small words it would be like, a email loop is a loop resulting to the uses of mail servers, scripts, and so on. It triggers  a automatic email response for say when you are away.

Glad I could help:

Yours,

Nathaniel

all options are correct a) b) c) and d)