Assertion: Necrosis occurs due to deficiency of Ca, Mg, Cu and K.
Reason: Necrosis is the death of tissue, particularly leaf tissue.

Options

A. If both assertio and reason are true and reason is the correct explanation of assertion
B. if both assertion and reason are true but reason is not the correct explanation of assertion
C. if assertion is true but reason is false
D. if both assertion and reason are false

Explanation

To solve the question regarding the assertion and reason about necrosis, we can follow these steps:

### Step 1: Understand the Assertion
The assertion states that necrosis occurs due to the deficiency of calcium (Ca), magnesium (Mg), copper (Cu), and potassium (K).

### Step 2: Analyze the Reason
The reason provided is that necrosis is the death of tissue, particularly leaf tissue.

### Step 3: Evaluate the Assertion
Necrosis is indeed associated with the deficiency of essential nutrients. Calcium, magnesium, and potassium are known to play critical roles in plant health, and their deficiency can lead to necrosis, particularly in leaf tissues.

### Step 4: Evaluate the Reason
The reason correctly defines necrosis as the death of tissue, especially in leaves. This is a true statement.

### Step 5: Determine the Relationship
While both the assertion and reason are true, the reason does not directly explain why necrosis occurs due to the deficiency of the mentioned nutrients. The assertion is about the cause (nutrient deficiency), while the reason explains what necrosis is (death of tissue).

### Conclusion
Both the assertion and reason are true, but the reason is not the correct explanation for the assertion. Therefore, the correct option is that both assertion and reason are true, but the reason is not the correct explanation of the assertion.

### Final Answer
The correct choice is: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

---