D
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

### Question:
A 10 g sample of aluminum and a 10 g sample of iron were each heated by 100 joules of energy. The temperature of the aluminum sample rose 11°C, while the temperature of the iron sample increased 23°C. Which statement best accounts for these results?

### Choices:
A. Iron is twice as dense as aluminum.
B. Atoms of aluminum are smaller than atoms of iron.
C. Using equal masses results in similar heat capacities.
D. The specific heat of iron is less than that of aluminum.

### Answer:
