[A]: Vernalization is also called as yarovization.
[R]: In short day plants the dark period re- quired is important

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 analyze the statements provided in the question, we need to evaluate both the assertion (A) and the reason (R) regarding their truthfulness and their relationship to each other.

**Step 1: Understand the Assertion (A)**
- The assertion states that "Vernalization is also called as yarovization."
- Vernalization is indeed a process that involves the induction of flowering in plants after exposure to prolonged cold temperatures. The term "yarovization" is often used in Russian contexts to refer to a similar process, particularly in relation to certain crops. Therefore, the assertion is **true**.

**Step 2: Understand the Reason (R)**
- The reason states that "In short day plants the dark period required is important."
- Short day plants require a longer duration of darkness (night) than light for flowering to occur. This means that the dark period is indeed crucial for these plants to flower. Therefore, the reason is also **true**.

**Step 3: Evaluate the Relationship Between A and R**
- While both statements are true, we need to determine if the reason provided (R) correctly explains the assertion (A).
- Vernalization (A) is specifically related to the requirement of cold temperatures for flowering, while the reason (R) discusses the necessity of dark periods for short day plants. These are different processes; thus, the reason does not explain the assertion.

**Conclusion:**
- The assertion (A) is true.
- The reason (R) is true, but it does not provide a correct explanation for the assertion (A).

**Final Answer:**
- Assertion (A) is true, and Reason (R) is true, but Reason (R) is not the correct explanation for Assertion (A).

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