What part of a word typically modifies its meaning?

The correct choice indicates that all the identified parts of a word—suffix, root, and prefix—can modify its meaning in different ways.

A suffix is a group of letters added to the end of a word. For example, adding "-ed" to "play" turns it into "played," shifting the word's meaning from present to past tense. This change clarifies when the action occurred, thereby modifying the meaning of the original word.

A root is the fundamental part of a word that contains its core meaning. For instance, in the word "unhappiness," "happy" serves as the root, conveying the main idea of joy. Modifying the root with that prefix alters the emotional context to its opposite.

A prefix is a set of letters added to the beginning of a word. In this case, "un-" in "unhappy" suggests negation, indicating that the original positive state of being happy is transformed. This alters the meaning of the word significantly.

Since all three parts—suffixes, roots, and prefixes—contribute to the meaning of a word in various ways, the correct answer encompasses all these components as means to modify meanings.