Anti-cholinesterase with central action?

Anti-cholinesterase with central action ?
a) Neostigmine
b) Physostigmine
c) Pyridostigmine
d) Edrophonium
Correct Answer - B
Ans. B. Physostigmine
Lipid soluble agents (organophosphates and physostigmine) have
more marked muscarinic and CNS effect; and stimulate ganglia but
action on skeletal muscle is less prominent.