Which describes the foramen magnum? large opening at the base of the skull that the spinal cord passes through shallow depression on the skull to which the jaw bone attaches large projection on the skull to which the jaw muscles attach tiny spaces between the fused bones of the skull

The foramen magnum is the large opening at the base of the skull that the spinal cord passes through. It is located at the occipital bone of the skull and the spinal cord pass through it after exiting the cranial cavity. Besides the spinal cord, several arteries along with alar ligament and tectorial membrane also pass through it.The position of the foramen magnum is also essential as it influences posture and locomotion. In humans that stand erect and are bipedal in nature, it is located in the front.  

The answer is energy. the arrows are showing how exited and energized the stones are.