Irene wants to buy some fish and a package of fish food for her aquarium. Each fish costs $15, and the fish food costs $10. If she needs to keep her expenses below $100, which inequality represents her situation?
A.) 15x < 100 + 10
B.) 15x > 100 + 10
C.) 15x + 10 < 100
D.) 15x + 10 > 100