**Question:** Arrangement of lens from eye to source of light, in light microscope

**Core Concept:** In a light microscope, the lenses are arranged in a specific manner to focus and magnify the light before it reaches the specimen and finally the observer's eye.

**Why the Correct Answer is Right:**
A. Objective Lens (Option C) is the primary lens, responsible for bringing the light source and specimen closer together. It has a high numerical aperture (NA) and a short focal length.
B. Eye Lens (Option D) is the second lens, which further magnifies the image formed by the objective lens and brings it into sharp focus for the observer. It has a low NA and a long focal length.

**Why Each Wrong Option is Incorrect:**
1. Objective Lens (Option A) is incorrect because it is the primary lens, not the one placed farthest from the specimen.
2. Intermediate Lens (Option B) is incorrect because it is the second lens, following the objective lens, and not the one that brings the image into sharp focus for the observer.
3. Eye Lens (Option D) is incorrect because it is the second lens, magnifying the image, not the one that focuses the image.

**Clinical Pearl / High-Yield Fact:** A compound microscope consists of two types of lenses:

1. **Objective Lenses:** These lenses are located closer to the specimen and are responsible for magnification and focusing of the specimen. The lower magnification objective lenses (1X, 4X, 10X) are for general observation, while higher magnification lenses (40X, 100X) are for detailed examination of cell structures.
2. **Eyepiece Lens:** This lens is located closer to the observer and combines the images from the objective lenses to form a single, sharp image in the observer's eye. The eyepiece magnification is usually 10X, resulting in the total magnification of the microscope.

**Correct Answer:** Intermediate Lens (Option B) is placed between the objective lens and the eyepiece lens. It combines the images from the objective lenses and brings them into focus before they reach the eyepiece lens.

By understanding the arrangement of lenses in a light microscope, students can effectively operate and interpret the microscope, enhancing their clinical skills and comprehension of microscopic structures in histopathology, microbiology, and other related fields.