Choose the correct form of adverb for the given sentence.
They visit their parents quite ______.

Here in the sentence, we need an adverb of time to qualify the adjective 'quite'.
- Frequency(noun): The number of occurrences within a given time period
- Innocently(adv): In a not unlawful manner
- Regularly(adv): In a regular manner
- Sincerely(adv): With sincerity; without pretence.
- The visit to the parents is in a regular manner.
- Hence, Regularly is the most appropriate choice among all.