Answer:
a. presentation and demonstration
Step-by-step explanation:
It is correct to say that Frank is in the presentation and demonstration stage in the sales process, as the question says that he showed the customer the variety of available beds designed for children, that is, he presented the product to the customer and demonstrated that it would satisfy your needs, in this case the seller reiterates the value and benefits of the product so that there is interest on the part of the consumer in making the sale.