Why did the price term in the website not included in the contract become the price here? I don't understand what contract rule this is.

A homeowner visited the websites of numerous local plumbers for service and hourly rate information. The homeowner called one of the plumbers, told him she had found him through his website, and asked him to unclog a floor drain in her basement. The plumber responded, \"Okay, I'll be there tomorrow at three.\" The plumber unclogged the drain and gave the homeowner an invoice that reflected the hourly rate for his services as posted on his website. The homeowner refused to pay the full invoice amount, asserting that his hourly rate was higher than that charged by other local plumbers. The homeowner offered to pay him the average of those rates. The plumber demanded payment of the invoiced amount. Which of the following describes the compensation the plumber is entitled to receive from the homeowner? Compensation based on the reasonable value of the plumber's services, because in the absence of an agreement on price, a reasonable price will be supplied. A Compensation at the invoiced price, because the hourly rate posted on the plumber's website supplied the price term for the parties' agreement. C Compensation necessary to protect the plumber's reliance interest, because he rendered services based on the homeowner's implied promise to pay. Compensation necessary to protect the plumber's restitutionary interest, because there was no meeting of the minds between the parties on price. v Explanation B is correct. When the homeowner asked the plumber to unclog her drain, she agreed to the hourly rate set by the plumber on the website that the homeowner had visited for purposes of researching prices and services. Further, the homeowner told the plumber she found him through the website. Therefore, the homeowner will be deemed to have agreed to the hourly rate set by the plumber on the website that she admitted to reviewing prior to calling for his services. Ais incorrect. Since the plumber's hourly rate was available to the homeowner on the website and the homeowner used the website as the basis for contacting the plumber, this is not a case where there is no agreement between the parties as to price. C is incorrect. A reliance-based measure of damages does not apply because the parties had a bargained-for contract that included the hourly rate set by the plumber. D is incorrect. A restitution-based measure of damages does not apply because the parties had a bargained-for contract that included the hourly rate set by the plumber