I need help with question 7

(c) 7 times as many whips as leather jackets. 7. Mary enjoys growing silver bells (b) and cockle shells (c) in her garden. Her preferences are represented by the utility function u(b, c) = b + 100c -c2. Mary gets both kinds of seeds for free. Assume it takes 2 square feet to grow a cockle shell and 5 square feet to grow a silver bell. If Mary's garden initially had 90 square feet, but was increased to 120 square feet ... (a) she would only increase her planting of silver bells. Quas! (b) she would only increase her planting of cockleshells. (c) she would plant more silver bells and more cockleshells. (d) cockleshells would be an inferior good. (e) she would increase her planting of cockleshells and decrease her planting of silver bells