[A]: Fundamental factor in the vernalization is low temperature.
[R]: Vernalization is ineffective in the absence of oxygen, water and adequate supplies of carbohydrates for respiratory processes.

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

### Step-by-Step Solution:

1. **Understanding Vernalization**:
- Vernalization is the process that induces flowering in plants after they have been exposed to prolonged periods of low temperatures. This is crucial for certain plants to transition from the vegetative stage to the flowering stage.

2. **Identifying the Fundamental Factor**:
- The fundamental factor in vernalization is indeed low temperature. It is essential for the process to occur, as many plants require a cold period to trigger flowering.

3. **Exploring the Role of Other Factors**:
- While low temperature is critical, other factors such as oxygen, water, and carbohydrates also play significant roles in the overall health and metabolic processes of the plant during vernalization.

4. **Analyzing the Statements**:
- Statement [A]: "Fundamental factor in the vernalization is low temperature."
- This statement is **True** because low temperatures are necessary for the vernalization process.
- Statement [R]: "Vernalization is ineffective in the absence of oxygen, water, and adequate supplies of carbohydrates for respiratory processes."
- This statement is **False** because while oxygen, water, and carbohydrates are important for the plant's overall health and respiration, they are not the fundamental factors for the process of vernalization itself.

5. **Conclusion**:
- Based on the analysis, we conclude that Statement [A] is true and Statement [R] is false. Therefore, the correct answer is that [A] is true and [R] is false.