As Night blindness is due to deficiency of vitamin "A"
R Actually the term vitamin means vital minerals.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "night blindness is due to deficiency of vitamin A."
- This is a well-known fact in biology. Vitamin A is essential for vision, particularly in low-light conditions.

2. **Explaining Night Blindness**:
- Night blindness, or nyctalopia, occurs when there is a deficiency of vitamin A.
- Vitamin A is crucial for the production of rhodopsin, a pigment found in the retina that is necessary for seeing in dim light.
- Without sufficient vitamin A, the body cannot produce enough rhodopsin, leading to poor vision in the dark.

3. **Understanding the Reason**:
- The reason states that "the term vitamin means vital minerals."
- This statement is incorrect. The term "vitamin" does not refer to minerals; rather, vitamins are organic compounds that are essential for normal growth and nutrition.

4. **Evaluating the Statements**:
- Since the assertion is correct (night blindness is indeed due to vitamin A deficiency) and the reason is incorrect (the definition of vitamins is wrong), we can conclude the relationship between the two statements.

5. **Conclusion**:
- The correct option is that the assertion is correct, but the reason is wrong.

### Final Answer:
The correct option is: "Assertion is correct, reason is wrong."

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