What is the most important thing your skull does

The most important thing your skull does is keep your brain from injury.

Explanation:

Many people can argue that there are better uses but, if you have no brain then how can you think? How can you do anything. You would literally be a hunk of meat.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.