[A] : Vitamins A, D, E and K are fat soluble while vitamin B complex and C are water soluble.
[R]: Fat soluble vitamins can be stored white water soluble vitamins can be excreted out through urine it they are 'in excess quantity.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the given question regarding the assertion and reason about vitamins, we will follow a systematic approach.

### Step-by-Step Solution:

1. **Identify the Assertion and Reason**:
- **Assertion (A)**: Vitamins A, D, E, and K are fat-soluble while vitamin B complex and C are water-soluble.
- **Reason (R)**: Fat-soluble vitamins can be stored while water-soluble vitamins can be excreted out through urine if they are in excess quantity.

2. **Evaluate the Assertion**:
- The assertion states that vitamins A, D, E, and K are fat-soluble. This is true as these vitamins dissolve in fats and oils and can be stored in the body’s fatty tissues.
- It also states that vitamin B complex and C are water-soluble. This is also true as these vitamins dissolve in water and are not stored in the body.

3. **Evaluate the Reason**:
- The reason states that fat-soluble vitamins can be stored while water-soluble vitamins can be excreted through urine if they are in excess. This is also true. Fat-soluble vitamins can be stored in the liver and fatty tissues, while excess water-soluble vitamins are excreted through urine.

4. **Determine the Relationship**:
- The reason provided explains why the assertion is true. Since fat-soluble vitamins can be stored, they do not require daily intake in the same way that water-soluble vitamins do, which need to be consumed regularly as they are excreted when in excess.

5. **Conclusion**:
- Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
- **Option A**: Both assertion and reason are true, and the reason is the correct explanation of the assertion.