Final answer:
B. #11. The #4 handle is compatible with the #11 blade.
Step-by-step explanation:
The correct answer is Option B: #11.
Blades used in medical settings, such as for surgical procedures or other medical interventions, are attached to handles. Each blade has a specific size and shape which determines its purpose and use. The number system for blades represents their size and is standardized across different manufacturers. In this case, a #4 handle is compatible with a #11 blade.
It's important to note that the compatibility of blades and handles can vary among different brands, so always refer to the manufacturer's guidelines and instructions when using medical equipment.