It depends on how you look at evolution. I would say B would be my answer. but it also depends on the course you take. Mine was a Christian based course. So I learned that evolution wasn't a thing.
A compound microscope is used for viewing small objects as it magnifies the image and makes it easy to observe them.
The diaphragm is a part of the compound microscope which is used for adjusting the amount of light so that one can view the specimen in a suitable manner.
The light source is located just under the stage where the slide is placed and the rotation of the diaphragm allows to adjust the intensity of the light illuminating the specimen.
