What is the smallest prime number?

The smallest prime number is 2 because it fits the definition of a prime number, which is a natural number greater than 1 that has no positive divisors other than 1 and itself. The number 2 meets these criteria perfectly, as its only divisors are 1 and 2. It is also noteworthy that 2 is the only even prime number; all other even numbers can be divided by 2, thereby having at least three divisors (1, the number itself, and 2), which disqualifies them from being prime.

The other options do not align with the definition of prime. The number 1 is not considered prime because it only has one positive divisor, itself. The number 3 is a prime number, but it is larger than 2, making it not the smallest. Similarly, 5 is also a prime number but larger than both 2 and 3. Therefore, the identification of 2 as the smallest prime number is correct due to its unique properties among natural numbers.