To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Email should never be considered anything like a phone call - This option is incorrect because email can share some similarities with phone calls.
Option B) You should know your emails are private - This option is not directly related to how email should be considered like a phone call.
Option C) The tone should always be informal and comfortable - This option is incorrect because the tone of an email can vary depending on the context and recipient, just like in phone calls.
Option D) Emails should be short, concise, and to the point, like phone calls - This option is correct because both phone calls and emails are often used for quick communication. Just like phone calls, emails should be written in a concise and to-the-point manner to effectively convey information.
The correct answer is D) Emails should be short, concise, and to the point, like phone calls. This option is correct because it highlights the similarity between the two modes of communication when it comes to brevity and efficiency.