Which of the following is a correct procedure for the operation of a microscope? a. first, put the specimen into focus using a high power lens, then switch to a lower power lens if needed. b. remove and add slides while the high power lens is selected. c. first, put the specimen into focus using a low power lens, then switch to a higher power lens if needed. d. use the fine focus knob with the low power lens and use the coarse focus knob with the high power lens

The correct answer is C "first put the specimen into focus with a low power lens, then switch to a high power lens"

The low power lens allows a broad spectrum view of the specimen, allowing the user to zoom into a place of interest in switching to a high power lens. This is the same way you would locate a point of interest if using binoculars; first you spot something of interest with your eyes (low power lens), then you switch to your binoculars (high power lens) for a closer look.