Final answer:
An anatomist is likely to observe the epicardium's role as a protective outer covering of the heart that secretes serous fluid, fitting the field's focus on the physical structures and parts of organisms.
Step-by-step explanation:
The observation most likely to be made by an anatomist is C: The heart's epicardium forms a protective outer covering and secretes serous fluid.
An anatomist specializes in the structure of organisms and their parts, so observations about physical structures, such as the epicardium of the heart and its functions, align with the focus of anatomical studies.
The epicardium is part of the pericardium, which consists of two layers; the epicardium is the visceral layer that closely covers the heart muscle.
Its role in providing a protective layer and secreting serous fluid to reduce friction between the heart and pericardium is within the scope of anatomy.
In contrast, the other options relate to molecular biology, neurobiology, and auditory physiology, which tend to be the subject matter for other specializations within the bioscience field.