Answer:
Quite.
Step-by-step explanation:
An adverb is one of the parts of speech in English language and it can be defined as a word that modifies a verb, adjective, or another adverb. Some examples are slowly, quickly, brightly, sadly, etc.
Hence, the word "quite" in the statement; "I don’t think it was a difficult test. In fact, I think it was quite easy." is an adverb.
In this scenario, quite modifies the adjective easy and it simply means the test was not difficult.