The set of prime numbers less than 99 is :

Options

A. Null set
B. Finite set
C. Infinite set
D. None of these.

Answer

To find the set of prime numbers less than 99, we will follow a systematic approach to identify all the prime numbers in that range.

### Step-by-Step Solution:

1. **Understanding Prime Numbers**:
- A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

2. **Starting from the Smallest Prime**:
- The smallest prime number is 2. We will start listing the prime numbers from here.

3. **Listing Prime Numbers**:
- We will list the prime numbers one by one until we reach the largest prime number less than 99.
- The prime numbers are:
- 2 (the only even prime)
- 3
- 5
- 7
- 11
- 13
- 17
- 19
- 23
- 29
- 31
- 37
- 41
- 43
- 47
- 53
- 59
- 61
- 67
- 71
- 73
- 79
- 83
- 89
- 97

4. **Finalizing the Set**:
- Now we compile these numbers into a set. The set of prime numbers less than 99 can be written as:
\[ A = \{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97\} \]

5. **Determining the Type of Set**:
- Since we can count the number of elements in this set, it is a finite set.

### Final Answer:
The set of prime numbers less than 99 is:
\[ A = \{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97\} \]
This is a finite set.