A researcher is interested in the structure of the flagellar motor, a series of proteins embedded in the cell wall and plasma membrane of E. coli and many other prokaryotes. Which microscopic technique would be appropriate to determine which proteins of the flagellar motor are associated with the cell wall? A. scanning electron microscopy (SEM) because it would generate a 3D image of the surface of the cell wall at high magnification

B. phase-contrast microscopy because it would introduce contrast between the flagella and the bacterial cell

C. transmission electron microscopy (TEM) because it would provide a cross-section of the cell wall at high magnification

D. brightfield microscopy because it would show where the flagella are attached to the cell

(Answer is C)