In which part of a professional email should you try to be brief, but highly descriptive?

A. The domain B. The subject line C. The emoticons D. The blind carbon copy (bcc)

In an email, the (B) subject line should be brief, but highly descriptive. The subject line is the line that captures what the email is about and in most cases, determines whether or not the reader will open it. This is why it is important to be descriptive, but not that long. The emoticons have nothing to do with the email content and the bcc is a type of email reply/send option. The domain also has nothing to do with the email subject and content.