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

### Question:
Some of the thermal structure of Earth is the result of a combination of chemical composition, temperature, and pressure. Which is a boundary that best demonstrates a contact point between layers having relatively the same temperature and chemical composition?

### Choices:
A. lithosphere and mesosphere
B. inner core and outer core
C. outer core and mantle
D. mantle and crust

### Answer:
