B. No, they must always ride on the footpath.
C. No, they must give way to cars at all times when riding on the road.
A bicycle rider or motorbike rider has the same rights and responsibilities as other road users, although there are certain roads where bicycles are prohibited, for example motorways.
Not only are riders of two-wheeled vehicles far less visible because they have a smaller profile, there are other challenges for them when riding on the road.
Having only two wheels means they have less grip on the road and are more at risk of slippery surfaces (e.g. oil, diesel or gravel on the road), metal manhole covers and painted road markings. Whereas a car or truck will just slide sideways a bit, if the front wheel of a bike or motorbike slips out from underneath the rider, it will almost certainly mean they will crash.
If it's raining a motorcyclist's view could be compromised because of rain hitting the visor - helmets don't have wipers and the rider will have to manually wipe the visor. If the weather is really bad it can be distracting and tiring for the rider - much more so than in a car - and this increases the chance of a loss of confidence.
Strong winds affect rider's ability to ride in a straight line.
Undulating road surfaces and potholes create more danger for riders.
Obstacles in the road that have blown there (e.g. branches) or fallen there (e.g. items from a trailer) are more dangerous if a rider hits them than if a car or truck hits them.
Cyclists and motorcyclists cannot brake as quickly and have less grip cornering.
This video shows that in a straight line a fast bike will be way quicker than a fast car, but once you put corners into the mix (and wet weather), the car can pull back some of the difference created by a fast bike's power-to-weight ratio.
However, there are some advantages to riding a two-wheeled vehicle on the road: