Deb Y. answered 11/01/19
Kind and Creative ESL teacher
Hi. I would add to the other response that you should always ask "Would you like to leave a message?" after you explain that Jeremy (in the other answer given) is at lunch, or that he is not available. This is important in business (or anywhere) because if the caller leaves a message describing the issue he is calling about, Jeremy will be better able to prepare for the return call. There will be less wasted time going back and forth on the telephone without conveying information.
By the way, if the caller is calling for a personal reason, he can always say he doesn't wish to leave a message by saying "no thank you, I will call back later."
In your question, I would select "He is currently at lunch. May I take a message?"