Final answer:
The determination of the cause of a new emerging disease by scientists studying disease transmission is: a) Epidemiology
Step-by-step explanation:
Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations and the application of this study to the control of health problems. Epidemiologists investigate patterns and causes of diseases, including the identification of new emerging diseases and the study of disease transmission.
Pathogenesis refers to the development of a disease and the chain of events leading to its occurrence. It focuses on the mechanisms by which a disease develops.
Virology is the study of viruses, which includes their structure, classification, and how they infect and interact with host cells. While relevant to understanding emerging diseases, it does not specifically address the determination of the cause of a new disease.
Etiology is the study of the causes or origins of diseases. While related, epidemiology specifically focuses on the broader study of disease patterns and transmission in populations.
hence option A is the correct option.