Harper is opening a small retailing business in Hometown USA. To annoucne her grand opening, Harper places an advertisement in the newspaper quoting general percentages off of their normal sales prices. Many local residents come in and makes purhcases. Harper's grand opening is such a huge success that she is unable to totally satisfy the demand of the customers. Which of the following correctly applies to the situation?

a. Harper has made an offer to the people reading the advertisement.

b. Harper has made a contract with the people reading the advertisment

c. Harper has made an invitation seeking offers

d Any customer who demands the goods advertised and tenders the money is entitled to them