Which anatomical landmark can be felt through the scalp?

The external occipital protuberance is a notable anatomical landmark located at the back of the skull, specifically on the occipital bone. It serves as an attachment site for the ligamentum nuchae and the trapezius muscle. Because it is situated just beneath the skin of the scalp, it can be palpated or felt through the scalp.

In contrast, the frontal sinus is located within the frontal bone, deep within the structure of the skull, and is not accessible from the surface. Similarly, the nasal bone is part of the facial skeleton and lies beneath soft tissues, making it difficult to palpate through the scalp. The zygomatic arch, while more superficial than the other options, is also not accessible from the scalp, as it is located on the side of the face and appears more prominent laterally. This makes the external occipital protuberance the only correct choice for a landmark that can be felt through the scalp.