Final answer:
Biohazardous waste containers must have a C. red label to indicate the potential risk and ensure proper disposal. The red label helps prevent mishandling and contamination.
Step-by-step explanation:
The correct answer to the student's question is that all biohazardous waste containers must have a C. red label. A biohazard is any biological material that could potentially cause illness, such as disease-causing organisms found in used needles or laboratory-cultured bacteria. It's essential to recognize the international symbol for biohazards to ensure proper disposal of biohazard waste. This waste needs to be sterilized by an autoclave before it can be safely disposed of in the waste stream. The red label is indicative of the potential biological risk and assists in preventing the mishandling of hazardous material.