The answer to this is frontal bone. This is the bone that protects the frontal portion of the brain. It may seem like one big portion but this is made out of two parts namely the orbital part and the squamous part. Some may think that this only protects the forehead but it also provides protection to the orbital cavity where the eyes can be found and also a portion of the nose.
Take note that the skull is composed of 8 major parts and this is just one of the parts that specifically protect a certain portion of the head especially the nervous tissues found in the brain and face.