Reason, why hair loss is more in old age:

Options

A. Reduction of blood supply
B. Decrease in protein synthesis
C. Low energy synthesis
D. Reduced storage of glycogen

Answer

### Step-by-Step Solution:

1. **Understanding Hair Loss**: Hair loss, also known as alopecia, can occur due to various factors including genetics, hormonal changes, and medical conditions. It is particularly common in older adults.

2. **Role of Hair Follicles**: Hair follicles are the structures from which hair grows. They require adequate nutrition and oxygen to function properly and produce hair.

3. **Importance of Blood Supply**: The hair follicles receive nutrients and oxygen through blood vessels (capillaries) in the scalp. A healthy blood supply is essential for maintaining the health of hair follicles.

4. **Effects of Aging**: As people age, the blood supply to various parts of the body, including the scalp, may decrease. This reduction in blood flow means that hair follicles receive less oxygen and fewer nutrients.

5. **Consequences of Reduced Blood Supply**: A lack of adequate blood supply can lead to hair thinning and increased hair loss. The hair follicles may not be able to sustain healthy hair growth, leading to baldness or thinning hair.

6. **Conclusion**: Therefore, the primary reason why hair loss is more prevalent in old age is due to the reduction of blood supply to the hair follicles.

### Answer:
The correct answer is **a. Reduction of blood supply**.

---