If a new nutrient is discovered, it would be -

Options

A. Micronutrient
B. Macronutrient
C. rare gas
D. a or b

Answer

To answer the question regarding the discovery of a new nutrient, we can follow these steps:

### Step 1: Understand the Types of Nutrients
- Nutrients are classified into two main categories based on their required amounts by plants: macronutrients and micronutrients.
- Macronutrients are required in larger quantities (more than 10 millimoles per kg), while micronutrients are needed in smaller amounts (less than 10 millimoles per kg).

### Step 2: Analyze the Options
- The options provided are:
1. Micronutrient
2. Macronutrient
3. Rare gas
4. ARB (which is not a recognized category of nutrients)

### Step 3: Eliminate Incorrect Options
- Rare gases are not considered nutrients for plants, so this option can be eliminated.
- ARB is not a recognized term in the context of plant nutrition, so this option can also be eliminated.

### Step 4: Determine the Correct Category
- Since the question asks about a new nutrient, it could either be a macronutrient or a micronutrient depending on the quantity required by the plant.
- If the new nutrient is required in large amounts (more than 10 millimoles per kg), it would be classified as a macronutrient.
- If it is required in smaller amounts (less than 10 millimoles per kg), it would be classified as a micronutrient.

### Step 5: Conclusion
- Therefore, the correct answer to the question is that if a new nutrient is discovered, it would be either a macronutrient or a micronutrient (options 1 or 2).

### Final Answer
- The correct answer is: **Option 1 (Micronutrient) or Option 2 (Macronutrient)**.

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