The correct answer is:

b) A number that expresses the part of a whole.

A fraction represents a part of something whole. It consists of two parts: a numerator (the top part) and a denominator (the bottom part). The numerator shows how many parts we have, while the denominator shows how many equal parts the whole is divided into.

Would you like more details or have any further questions?

Here are 5 related questions:

1. What is a numerator in a fraction?
2. What does the denominator in a fraction represent?
3. How do you simplify a fraction?
4. How can you convert a fraction into a decimal?
5. What is the difference between a proper and improper fraction?

Tip: In a fraction, if the numerator is smaller than the denominator, the value of the fraction is less than 1.