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

### Question:
Students are performing an investigation to determine the types of bacteria that grow inside their school. Which activity should the students avoid while performing this investigation?

### Choices:
A. wearing gloves while handling the samples
B. cleaning all materials they have finished using
C. bringing food and drinks into the laboratory
D. washing hands before leaving the laboratory

### Answer:
