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

### Question:
A hard hat would be used to protect a student during which type of investigation?

### Choices:
A. a field trip to a museum of geology
B. a field investigation of rock layers in a hillside
C. a laboratory demonstration on the hardness of minerals
D. a laboratory investigation of the identification of fossils

### Answer:
