Final answer:
The magnification of the cell is 500x.
Step-by-step explanation:
The magnification of a microscope is calculated by dividing the image size by the actual size of the object being viewed. In this case, the diameter of the cell is 10µm, which is equal to 0.01mm. The cell is measured at a distance of 500mm on the microscope.
Using the formula for magnification: magnification = image size / actual size, we can calculate the magnification.
Magnification = 500mm / 0.01mm = 50000x
Therefore, the correct answer is (c) 500x.