Which of the following is a root word?

Without the list of options, it is not possible to determine which word is a root word. Please provide the options.

To answer your question, I would need a list of the options you are referring to. Please provide the available options so that I can assist you further.

To determine which of the following is a root word, we need to understand what a root word is first.

A root word is the basic part of a word from which other words are formed. It is usually the core or main part of the word that carries the central meaning.

In order to identify a root word among the options given, we should look for the most basic and meaningful part of each word. Let's examine the options to find the root word:

1. Unhappiness: The root word here is "happy." The prefix "un-" is added to "happy" to change its meaning to the opposite, but "happy" on its own is the base root word.

2. Careful: In this case, the word "care" serves as the root word. The suffix "-ful" is added to "care" to modify its meaning.

3. Education: The root word in this example is "educate." The suffix "-ion" is added to "educate" to transform it into a noun form.

By analyzing each option, we find that the root word among the given choices is "happy" in "unhappiness."