The scanning, low, and high power objectives are mounted on the:

• A. stage
• B. coarse adjustment knob
• C. revolving nosepiece
• D. ocular lens

Answer: (C)

Verified step by step guidance

1. Understand the components of a compound light microscope: The microscope has several parts, including the stage (where the slide is placed), the coarse adjustment knob (used for focusing), the ocular lens (eyepiece), and the revolving nosepiece (which holds the objective lenses).
2. Identify the function of the revolving nosepiece: The revolving nosepiece is a rotating part of the microscope that holds the objective lenses (scanning, low, and high power). It allows the user to switch between different magnifications by rotating the nosepiece.
3. Clarify the role of the objective lenses: The scanning, low, and high power objectives are different magnifications used to view specimens. These lenses are mounted on the revolving nosepiece for easy switching during observation.
4. Eliminate incorrect options: The stage is where the slide is placed, not where the objectives are mounted. The coarse adjustment knob is used for focusing, and the ocular lens is the eyepiece through which you look, so these are not correct answers.
5. Conclude that the correct answer is the revolving nosepiece, as it is specifically designed to hold and rotate the objective lenses for magnification adjustments.