Answer:
the considerate.
Step-by-step explanation:
The considerate - 
According to english language , the meaning of considerate is being very polite , calm and caring. 
Hence, from the scenario of the question, 
The salespeople need to adapt considerate , i.e. tries to be calm and compose , in order to sell their product , which act as their strategy of selling the product. 
Hence, 
The correct term is the considerate.