Answer: B. We can make a lot of money from this retail opportunity.
Step-by-step explanation:
Even though retail means to sell something, it is not a general substitute for the word sell. Retail refers to the act of selling or engaging in a business opportunity that requires some form of sales.
When used in a sentence, it should relate to that act rather than be used as a substitute for ''sell''. For instance, ''Jack engaged in retail by selling the cow''. Retail should refer to or describe the action - which is why it is an adjective -instead of being the action word as is the case in option 2.