Final answer:
The least likely quality to be attributed to an effective nursing leader is B) pessimism and stress.
Step-by-step explanation:
The least likely quality to be attributed to an effective nursing leader is Pessimism and stress. Nursing leaders need to have a positive attitude and the ability to handle stress, as they are responsible for managing teams and making critical decisions in high-pressure situations. Energy and integrity, courage and initiative, and optimism and perseverance are all qualities that would be valuable for an effective nursing leader.