Answer: a. Sales prospect
When a potential customer becomes serious about the purchase and is likely to buy the product, the customer becomes a sales prospect.
Explanation:
A sales prospect is known to be an act of looking out for new customers, persuading them to buy products and in the process, they become potential customers. There are various method in which a salesperson or seller can get a potential prospects, some of which are through referral and direct contact with the prospects. Hence, sales prospects increase and improve the number of customers that a company has.