73, 77, 79, 83, 89, 97

Options

A. 73
B. 77
C. 79
D. 83

Explanation

To solve the problem, we need to analyze the given series of numbers: 73, 77, 79, 83, 89, 97.

### Step-by-Step Solution:

1. **Identify the Series**: The first step is to identify the nature of the series. The numbers given are: 73, 77, 79, 83, 89, and 97.

2. **Check for Prime Numbers**: We need to determine if each number in the series is a prime number. A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.

3. **Evaluate Each Number**:
- **73**: Check factors. The only factors are 1 and 73. Thus, 73 is a prime number.
- **77**: Check factors. The factors are 1, 7, 11, and 77. Since it has factors other than 1 and itself, 77 is not a prime number.
- **79**: Check factors. The only factors are 1 and 79. Thus, 79 is a prime number.
- **83**: Check factors. The only factors are 1 and 83. Thus, 83 is a prime number.
- **89**: Check factors. The only factors are 1 and 89. Thus, 89 is a prime number.
- **97**: Check factors. The only factors are 1 and 97. Thus, 97 is a prime number.

4. **Conclusion**: From the evaluation, we see that all numbers in the series are prime except for 77. Therefore, 77 is the incorrect number in the series.

5. **Final Answer**: The number that does not belong in the series is **77**.