Answering phone calls for others

This episode is about answering phone calls for others. Nguyen Truong Giang, from Vietnam, is an IT engineer who works at a marketing firm. Giang-san studied Japanese and programming in university. He moved to Japan in 2015 and now serves as a link between the Vietnam branch of his company and the Japanese headquarters. Giang-san's Japanese is good, but he still needs experience with phone manners. In a telephone roleplay challenge, what will he do when a call comes in for a coworker who is busy on another line?