Which of the following is most likely to be an observation made by an anatomist?

a)rna polymerase binds to a promoter, a dna sequence that becomes a gene.
b)sensory receptors convert information into impulses to be sent to the cns.
c) the heart's epicardium forms a protective outer covering and secretes serous fluid.
d)the middle ear is an air-filled space that separates the outer and inner ear.