Which of the following describes a prime number?

A prime number is defined as a whole number greater than 1 that has exactly two positive factors: 1 and itself. This means that a prime number can only be divided evenly by 1 and the number itself, with no other divisors. For example, the number 5 is prime since its only factors are 1 and 5.

Option B accurately describes this definition, indicating that prime numbers are indeed whole numbers greater than 1 with just two positive factors. This characteristic is what sets prime numbers apart from composite numbers, which have more than two factors. In contrast, the other options do not align with the established definition of prime numbers. Option A incorrectly states that prime numbers can be less than 1, while Option C describes composite numbers instead. Option D introduces decimals, which are not relevant to the definition of prime numbers, as primes must be whole numbers.