Final answer:
Fecal specimens are examined at a power of 100X and then changed to 400X to get a better visualization of the specimen or to scan for smaller specimens.
Step-by-step explanation:
When examining fecal specimens, the power of the microscope is typically increased to get a better visualization of the specimen or to scan for smaller specimens. The correct answer is option c, where the specimens are examined at a power of 100X and then changed to 400X.