If you eventually plan to take all four parts of the exam, you can check all four boxes. After you pass one part of the exam you have 18 months to take and pass the other three parts. See the 18 month requirements below (How do I calculate the 18 months rolling window?).
Though you may not notice, as bulbs age they don't generate as much light as when they were new. That means your headlights may still work after five or six years, but they may not be as bright or illuminate as much of the road as they used to.
While it can vary slightly depending on the bulb, on average LED light bulbs last over 50,000 hours. That would be almost six years if left on twenty-four hours, seven days a week. In terms of usage, if you leave your light on all day (16 hours), an LED replacement bulb would last 3,125 days or approximately 8.5 years. If you leave it on only during the evening (4 hours), an LED replacement bulb would last 35 years. Comparatively speaking, both incandescent and compact fluorescent light bulbs last a mere fraction of that. LEDs last 50 times longer than a traditional incandescent bulb and 10 times longer than a compact fluorescent.