Which of the following best defines a prime number?

A prime number is specifically defined as a natural number greater than 1 that has exactly two distinct positive divisors: 1 and itself. This means that a prime number cannot be divided evenly by any other integer apart from these two. For instance, the number 7 is prime because its only divisors are 1 and 7.

The option stating that a prime number is a positive integer greater than 0 is too broad, as it includes numbers such as 1 and all composite numbers, which do not meet the criteria for being prime. The choice describing any whole number that can be divided evenly is also inaccurate, as this could refer to both prime and composite numbers. Finally, the option suggesting a natural number that can be expressed as a fraction is misleading, since prime numbers do not need to be expressed in fractional form—they must remain whole numbers greater than 1. Thus, focusing on the precise definitions allows us to correctly identify what constitutes a prime number.