It's probably Option C. Upgrading from a hybrid to a road bike won't really make much difference. There are some small gains in aerodynamics, but that's a matter of a few seconds over 28km. Depending on the tires you have now you might gain as much as 2 kph in average speed by switching to better tires. Clipless pedals are also a relatively small gain. Unless you feel like you're worried about your feet slipping off the pedals when you try to ride faster, clipless pedals won't really do a lot for you in terms of speed.

My guess would be that you need to train your body to ride faster. This isn't just about fitness. Riding fast requires a particular style of riding. You need good form and good cadence. A lot of casual riders are comfortable mashing along at around 60 pedal strokes per minute. That's fine if it's comfortable for them, but if you want to optimize your speed you should be spinning more like 90 times a minute.

Beyond that, it's a matter of pushing yourself. Riding every day doesn't make you any faster unless you are pushing your limits. If you're not a racer you probably think that you don't need to be training in the traditional sense, but the way that racers get faster is the same way that the rest of us get faster. They just do it more methodically. The key seems to be intervals. Use your favorite search engine to look up information on interval training. If you want to get faster that's the way to do it.