What is the definition of a proper fraction?

A proper fraction is defined as a fraction in which the numerator is less than the denominator, meaning its value is always between zero and one. This characteristic aligns with the selection that describes a fraction whose absolute value is greater than or equal to zero and less than one.

In this definition, the stipulation about the absolute value being non-negative underscores that proper fractions cannot be negative, reinforcing that they indeed only fall within the range from zero up to, but not including, one whole. This is essential in distinguishing proper fractions from improper fractions, which do encompass values greater than or equal to one. Thus, the correct answer captures the specific constraints and nature of proper fractions succinctly.