Final answer:
The nurse would advise disposing of used syringes in a puncture-resistant sharps container to safely handle the biohazard and prevent the spread of infection. This is the most appropriate method to avoid injuries and contamination. Therefore, the correct option is a.
Step-by-step explanation:
The nurse would instruct a client with type 1 diabetes to dispose of a used syringe in a puncture-resistant sharps container. This is the safest option because used syringes are considered biohazards, as they can harbor blood contaminated with disease-causing organisms. It is important to follow proper disposal methods to prevent injury and the spread of infection. Other options such as recycling bins, trash bins, or biohazard bags are not suitable for sharps due to the risk of puncture and the potential to expose others to biohazard materials.