**Core Concept**
A blow out fracture of the orbit is a type of fracture that occurs when there is a break in one or more of the bones that form the orbit, the bony cavity that contains the eyeball and its associated structures. This type of fracture typically occurs when there is a sudden increase in pressure within the orbit, such as during a blunt trauma to the face.

**Why the Correct Answer is Right**
The most common bones to be fractured in a blow out fracture of the orbit are the lamina papyracea, which is a thin, fragile bone that forms the medial wall of the orbit. The lamina papyracea is prone to fracture due to its thinness and the fact that it is subjected to a significant amount of pressure during a blow to the face. The fracture of the lamina papyracea can lead to herniation of orbital contents, including the orbital fat, into the maxillary sinus.

**Why Each Wrong Option is Incorrect**
**Option A:** The zygomatic bone is a common site of fracture in facial trauma, but it is not the most common bone to be fractured in a blow out fracture of the orbit.

**Option B:** The frontal bone forms the roof of the orbit, but it is not typically involved in a blow out fracture.

**Option C:** The maxillary bone forms the floor of the orbit, but it is not the most common bone to be fractured in a blow out fracture.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that a blow out fracture of the orbit can lead to complications such as herniation of orbital contents, increased intraorbital pressure, and vision loss if left untreated.

**Correct Answer:** C.