In the word chronology, "ology" is which of the following?

1. A root word
2. A base word
3. A suffix
4. A prefix

3. A suffix

In the word "chronology," "ology" is a suffix.

To identify if "ology" is a root word, base word, suffix, or prefix in the word "chronology," we can break down the word into its components.

"Chronology" is a noun that refers to the study of the arrangement of events in the order of their occurrence over time.

Let's analyze the components:

1. "Chrono" - This component refers to 'time,' as seen in words like 'chronological' or 'chronometer.'
2. "-logy" - This component is used to form nouns that denote a subject of study or a science.

Considering this breakdown, we can determine that "ology" is a suffix in the word "chronology."

Therefore, the correct answer is: 3. A suffix