Final answer:
The nurse fulfills Maslow's need for love and belongingness by encouraging a widowed patient to join a bereavement support group, providing them with an emotional support network and a sense of belonging.
Step-by-step explanation:
The action of the nurse that addresses Maslow's need for love and belongingness is when the nurse encourages a widowed patient to join a bereavement support group. Maslow's hierarchy of needs outlines love and belongingness as critical emotional and psychological needs where individuals seek companionship and acceptance from others. Encouraging a widowed patient to join a bereavement support group would provide them with an emotional support network, meet their psychosocial needs, and offer them a sense of community wherein they can share mutual interests and concerns, thus fulfilling their need for love and belongingness.