Because Melissa is intrigued with how people change from infancy through late adulthood, she should study <u><em>life span</em></u> development.
Explanation:
Lifespan development can generally be described as a term which refers to the processes pr steps of development which occur in humans from conception till death. Lifespan development study includes all the fields like behavioural, emotional, mental, physical aspects of development. Even the issues related to health and mind are a part of lifespan development study. Hence, it will be best for Melissa to study lifespan development.
