The smallest prime number is

Explanation: A prime number is a number whose factors are 1 and the number itself.  So first find how many of the given options are prime numbers by finding their factors.  If their factors have 1 and the number itself, then those numbers are primes.

To find the smallest prime number from the given options.

A. 1

•  1 is an odd number and 1 has only one factor that is 1 itself.
• 1 is not a prime number as well as not a composite number.

B. 2

• 2 is an even number and 2 have two factors : 1 and 2.
• As 2 have only two factors, it is a prime number.

C.3

•  3 is an odd number and 3 also have two factors : 1 and 3.
• As 3 also have only two factors, it is also a prime number.

D.4.

• 4 is an even number and 4 have three factors : 1, 2 and 4.
• As 4 has three factors it is not a prime number. 4 is a composite number.

So finally we got two prime numbers, they are 2 and 3. 2 is smaller than 3. Therefore, 2 is the smallest prime number.

Final answer: So, the correct answer is “Option B” i.e. 2