Which of the Following Statements Is TRUE

Which of the following statements is TRUE?

A) Emails don't require salutations since they are not as formal as letters.
B) You should refrain from personal conversation in business emails.
C) Emails don't require sign-offs since they are not as formal as letters.
D) You should avoid using bullets in emails since these are considered too informal.
E) A signoff such as "cheers" is too informal to use for emails.