Step 1: What is being asked.
The cranium is the part of the skull that holds and protects the brain. The question wants to know what kind of bones most of these are, based on how they form.
Step 2: Two ways bones can form.
Some bones form directly inside a sheet of connective tissue. This is called intramembranous ossification, and such bones are named dermal or membrane bones. Other bones first appear as cartilage and then turn to bone, and these are called endochondral bones.
Step 3: How cranial bones develop.
The flat bones of the skull roof, like the frontal and parietal bones, form straight inside membrane without a cartilage stage. So they are dermal bones.
Step 4: Why option 1 is right.
Since most cranial bones follow the membrane route, dermal bones is the correct choice.
Step 5: Why the other options are wrong.
Endochondral bones form from cartilage, which is mainly the case for limb bones, not the skull roof. Sesamoid bones grow inside tendons, like the kneecap. Visceral bones belong to the gut or visceral skeleton. None of these describe most cranial bones.
Step 6: Conclusion.
Therefore the correct answer is "Dermal bones". \[ \boxed{\text{Dermal bones}} \]