Final answer:
The best fit for the study of identical twins Trinna and Suzanne, who were separated at birth, is a case study because it illustrates the importance of environmental factors on an individual's development, acknowledging the influence of both heredity and environmental factors on growth.
Step-by-step explanation:
The research method and explanation that best fit the scenario where Trinna and Suzanne, identical twins separated at birth and raised in different environments, are being studied is: b. A case study, because environment is more important than heredity. This is indicative of the significance of environmental factors on an individual's physical development.
Although they share identical genetic makeup, the difference in Trinna's stature compared to Suzanne's may be due to environmental influences, such as dietary preferences and nutritional intake during childhood. The case study approach is beneficial here because it allows for an in-depth investigation of the twins' unique circumstances, which may shed light on the complex interplay between genetics (nature) and environment (nurture).