Final answer:
The nurse should employ the Psychomotor domain option (B) when teaching a patient how to bandage a wound at home, as this involves teaching a physical skill and motor coordination.
Step-by-step explanation:
When teaching a patient how to bandage a wound such as gangrene on his toes, the nurse should use the Psychomotor domain option (B). This domain involves physical movement, coordination, and the use of motor-skill areas. Bandaging is a physical skill that requires demonstration and practice, falling squarely under this domain of learning. The nurse would need to provide hands-on demonstrations and allow the patient to practice with guidance to ensure proper technique and adherence to recommended procedures for treating the wound.