How often must firearm registrations be renewed in Hawaii?

In Hawaii, firearm registrations do not expire. This means that once a firearm is registered in Hawaii, there is no requirement to renew the registration periodically. This is what sets Hawaii apart from some other states that may require periodic renewal of firearm registrations. Therefore, option C is the correct answer in this case.

Options A, B, and D are incorrect because firearm registrations in Hawaii do not have to be renewed annually, every 5 years, or after a change of ownership.