The correct answer is B. Restart.
When you install new drivers, it is important to restart your computer so that the new drivers can be loaded and used. Restarting your computer also ensures that all of the changes made by the installation are applied.
Shut Down will power off your computer completely. This is not necessary after installing new drivers.
Sleep will put your computer into a low-power state. This can save energy, but it will not allow you to use your computer until you wake it up. It is not necessary to sleep your computer after installing new drivers.
Hibernate will put your computer into a very low-power state. This will save even more energy than sleep, and it will also allow you to resume your work exactly where you left off when you wake your computer up. However, it is not necessary to hibernate your computer after installing new drivers.
In conclusion, the best option after installing new drivers is to restart your computer. This will ensure that the new drivers are loaded and used, and it will also apply any changes made by the installation.