Answer:
B) so that dealers make an extra effort to sell the manufacturer's cars
Step-by-step explanation:
A stimulus is used to get an economic agent to work harder around a goal. This is very common in case of sales. When the auto industry stimulates its dealers, it is intended to get them to sell more of their cars. The stimuli are of different natures depending on the purpose, but are usually financial stimuli. For example, increasing dealer commission for each car sold is a stimulus.