Which of the following statements is incorrect?

Options

A. Every integer is a rational number.
B. Every natural number is an integer.
C. Every natural number is a real number.
D. Every real number is a rational number.

Answer

To determine which statement is incorrect, let's analyze each option step by step.

### Step 1: Analyze Option 1
**Statement:** Every integer is a rational number.

**Explanation:**
- A rational number is defined as a number that can be expressed in the form \( \frac{p}{q} \), where \( p \) and \( q \) are integers and \( q \neq 0 \).
- Any integer \( n \) can be expressed as \( \frac{n}{1} \), which fits the definition of a rational number.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Option 2
**Statement:** Every natural number is an integer.

**Explanation:**
- Natural numbers are the set of positive integers (1, 2, 3, ...).
- Integers include all natural numbers, negative numbers, and zero.

**Conclusion:** This statement is **correct**.

### Step 3: Analyze Option 3
**Statement:** Every natural number is a real number.

**Explanation:**
- Real numbers include both rational and irrational numbers.
- Since natural numbers are a subset of integers, and integers are a subset of real numbers, every natural number is indeed a real number.

**Conclusion:** This statement is **correct**.

### Step 4: Analyze Option 4
**Statement:** Every real number is a rational number.

**Explanation:**
- Real numbers include both rational numbers (like \( \frac{1}{2}, 3, -4 \)) and irrational numbers (like \( \sqrt{2}, \pi \)).
- Since not all real numbers can be expressed as \( \frac{p}{q} \), this statement is false.

**Conclusion:** This statement is **incorrect**.

### Final Answer
The incorrect statement is **Option 4**: "Every real number is a rational number."

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