Which Strategy Is NOT an Example of Price Discrimination

Which strategy is NOT an example of price discrimination?

A) a Fourth of July sale
B) a coupon in the newspaper offering a 10% discount on a product
C) a higher price for front row seats at a concert than for seats at the back
D) a lower price charged to the grandfather who bought his airline ticket to Chicago three weeks in advance and will stay over a Saturday night than to the businesswoman who bought her ticket the day of the flight and will not stay over Saturday night