Which of the following cases are examples of price discrimination?
1. A supermarket charging more for strawberries in December than in June.
2. A doctor charging for her services according to the income of her patients.
3. A fixed mortgage rate is higher than a variable mortgage rate.
◦ 1 only
◦ 2 only
◦ 3 only
◦ 1 and 3 only
◦ 1, 2, and 3