What Statement Best Describes a Best Practice of Instant Messaging

What statement best describes a best practice of instant messaging and texting use on the job?

A) Maintain one contact list for both professional and personal contacts to simplify things.
B) To use instant messaging and texting most efficiently on the job, make yourself available at all times during working hours.
C) Use ample jargon, slang, and abbreviations to make your instant messages and text messages as short as possible.
D) Because instant messages and text messages can be saved, don't say anything that could damage your reputation or that of your organization.