Final answer:
The nurse observes that the patient's social interactions fulfill the 'Love and belonging (option 2)' need according to Maslow's hierarchy of needs.
Step-by-step explanation:
The nurse recognizes that the adolescent patient, who is engaging with friends and experiencing laughter while hospitalized, is meeting the need for Love and belonging. This need, according to Maslow's hierarchy of needs, falls in the middle of the pyramid. It comes after the fulfillment of physiological and safety needs, and before the attainment of esteem and self-actualization. The social interactions and support system this patient has with their friends demonstrate the satisfaction of this psychosocial need, which is critical for their overall well-being.