1. (a) That's right. Deceit consists of knowingly leading another person into error. A plaintiff who brings an action for deceit must firstly prove that the defendant made a representation (statement of fact) knowing it was false (or with reckless disregard for the truth).
A plaintiff must also prove that the defendant intended the plaintiff to rely and act on the statement, and that s/he actually did so.
In the present case, since A would have known what his annual profits were, it is obvious that he knew his representation was untrue. Since A made the representation in the course of negotiating the sale of the business to the person interested in buying it, it can also be deduced that A made the statement with the intention of inducing B to offer a higher price than she otherwise would have paid.