At birth, which of the following is closest to its final adult level?

At birth, which of the following is closest to its final adult level?
(a) Brain weight
(b) Number of brain cells
(c) The number of bones
(d) Arm and legs length
✅ Correct Option: (b) Number of brain cells
Explanation: Most brain cells are present at birth, though connections (synapses) develop later.