What should be indicated when asking someone to relay part of a message?

When asking someone to relay part of a message, using the term "repeat" is appropriate. This term specifically instructs the person to say back or recite the message as it was originally communicated, ensuring that the information is accurately conveyed and understood. It emphasizes clarity and focus on the exact words of the message, which is crucial in communication, particularly in law enforcement and emergency situations where precision is key.

The other choices convey different meanings. "Busy" may indicate a lack of availability to communicate further, "relay" simply refers to the act of passing along a message without specifying that the message should be repeated as is, and "receiving well" suggests that the individual understood the message but doesn’t prompt them to convey it again. Each of these alternatives does not specifically encapsulate the need to articulate the previous message verbatim, which is why "repeat" is the correct action in this context.