Which of the following statements is incorrect ?

Options

A. Every integer is a rational number
B. Reciprocal of zero is not defined
C. The product of two rational numbers is always a rational number.
D. Every negative rational number is greater than zero.

Answer

To determine which statement is incorrect, we need to evaluate each of the provided statements one by one.

### Step-by-Step Solution:

1. **Evaluate the first statement**: "Every integer is a rational number."
- **Explanation**: An integer can be expressed as a fraction where the denominator is 1 (e.g., 3 can be written as 3/1). Since all integers can be expressed in this form, this statement is **true**.

2. **Evaluate the second statement**: "0 is equal to 1 upon 1."
- **Explanation**: The fraction 1/1 equals 1, not 0. Therefore, this statement is **false**.

3. **Evaluate the third statement**: "The product of two rational numbers is always a rational number."
- **Explanation**: If we take two rational numbers, say a/b and c/d, their product is (a/b) * (c/d) = (a*c)/(b*d). Since both a, b, c, and d are integers and b and d are not zero, the product is also a rational number. Thus, this statement is **true**.

4. **Evaluate the fourth statement**: "Every negative rational number is greater than zero."
- **Explanation**: A negative rational number, such as -2, is indeed less than zero. Therefore, this statement is **false**.

### Conclusion:
After evaluating all the statements, we find that:
- The first statement is true.
- The second statement is false.
- The third statement is true.
- The fourth statement is false.

The incorrect statements are the second and fourth. However, since the question asks for one incorrect statement, we can conclude that the **second statement** is the most straightforwardly incorrect.

### Final Answer:
The incorrect statement is: "0 is equal to 1 upon 1."

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