Final answer:
The correct option is d. A compound microscope has two lenses, an objective and an eyepiece. The objective lens focuses the image of the object and the eyepiece magnifies it further.
Step-by-step explanation:
A compound microscope works by having two magnifying lenses, an objective lens and an eyepiece. The objective lens focuses the image of the object and forms a larger first image, which serves as the object for the eyepiece. The eyepiece then magnifies the first image further to form the final magnified image.
For example, when looking through a compound microscope, the objective lens captures the image of the specimen and forms a larger first image. The eyepiece then magnifies this first image, allowing you to see a highly magnified view of the specimen.