Which of the following is a strategy for routine replies and positive messages?

A) Use the indirect approach.
B) Place your main idea in the opening of the message.
C) Open with an interesting fact or question.
D) Avoid embedding negative information in a positive context.

Placing the main idea in the opening of the message helps the recipient quickly understand the purpose of the message and can make the message more efficient. This strategy works well for routine replies and positive messages where the objective is to convey clear and concise information. The other strategies mentioned - using the indirect approach, opening with an interesting fact or question, and avoiding embedding negative information in a positive context - may be more appropriate for other types of messages.