Answer:
Request the colleague to call after sometime
Step-by-step explanation:
While working on a customer issue, your colleague calls and asks for help to resolve his issue. What should be done is to "Request the colleague to call after some time."
This is because,e in situations like that, it is believed that the customer should come first, and that is the purpose of being there. For employee to serve the customer. A colleague can easily link up with other employees to get his issues sorted, or simply wait.