**Question:** The highest concentrations of Vitamin A is seen in –

A. Liver
B. Pigmented cells (melanocytes)
C. Retina
D. Sebaceous glands

**Core Concept:** Vitamin A is a vital nutrient that plays a crucial role in maintaining healthy vision, immune function, and cell growth. It is obtained from dietary sources like liver, fish, fruits, and vegetables or synthesized internally from carotenoids like beta-carotene.

**Why the Correct Answer is Right:**

The correct answer is C. Retina, because the retina is a vital part of the eye responsible for vision. Vitamin A is a key component of rhodopsin, a protein involved in the visual pigment of rod cells in the retina. Rod cells are crucial for night vision and peripheral vision. Vitamin A deficiency can lead to night blindness and impaired vision.

**Why Each Wrong Option is Incorrect:**

A. Liver (Option A) is a good source of Vitamin A, but the highest concentration is found in the retina due to its direct involvement in vision.
B. Pigmented cells (melanocytes) (Option B) do not have the highest concentration of Vitamin A. While melanocytes contain Vitamin A, their role in vision is minimal compared to the retina.
D. Sebaceous glands (Option D) are involved in skin oil production and have a minor role in Vitamin A distribution compared to the retina.

**Clinical Pearl:**

Understanding the distribution of Vitamin A is crucial for recognizing its importance in vision and maintaining overall health. Vitamin A deficiency can lead to severe health consequences, such as xerophthalmia (eye disease) and night blindness. Ensuring a balanced diet rich in Vitamin A-rich foods like liver, fish, fruits, and vegetables is essential to maintain optimal health.