While on a service call at a customer site, you are discussing the problem with the customer when your cell phone rings. You check the caller ID$,$ and you see that the call is related to parts you ordered for another customer.

Which of the following is the MOST professional way to handle the situation?

Answer the phone and say, $"$I$\text{'}$m busy right now. I'll call you right back."

Immediately answer the phone and try to finish the call as fast as you can.

Ignore the phone and let it continue ringing until the caller reaches your voicemail.

Ask the customer if it is okay to take the call, and then step into the hallway to briefly talk on the phone.