A frustrated and angry customer calls in with a system that does not work. Which of the following is the FIRST course of action for a technician to take?（）

A. Transfer the customer to another technician, who can allocate more time to the issue.
B. Maintain a positive attitude and offer them the cheapest solution possible to satisfy them.
C. Listen to what the customer has to say and calmly recommend the best course of action.
D. Use technical language to demonstrate knowledge and expertise to the customer.