Every point on a number line represents as: (a) a unique real number         (b)  a natural number (c) a rational number               (d)  an irrational number

Explanation

To solve the question, we need to analyze what each option represents in relation to a number line.

### Step-by-Step Solution:

1. **Understanding the Number Line**:
- A number line is a visual representation of numbers where each point corresponds to a specific number. It includes all types of numbers: natural numbers, whole numbers, integers, rational numbers, and irrational numbers.

2. **Analyzing the Options**:
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