Find the odd number / letters / word from the given alternative:

The odd one out is Cranium.

• Tibia is the larger of the two bones in the lower leg.
• Cortex is the outer layer of the brain.
• Cerebellum is the part of the brain that controls balance and coordination.

The cranium is the skull, which is made up of several bones that protect the brain. It is not a part of the nervous system.