Final answer:
Dirty needles should be disposed of in a sharps container to ensure safe handling and prevent accidental needle stick injuries.
Step-by-step explanation:
The correct answer is D. Sharps container. Dirty needles should be disposed of in a sharps container to ensure safe handling and prevent accidental needle stick injuries. Sharps containers are specifically designed to hold used needles and other sharp medical instruments, and they are typically made of puncture-resistant materials to prevent leakage.