<prompt> Short acting anticholinesterase isTacrineEdrophoniumPyridostigmineDonepezil  <response>: B Edrophonium Pyridostigmine: Resembles neostigmine in all respects but is dose to dose less potent and longer acting, less frequent dosing is required in myasthenia gravis. Edrophonium: Resembles neostigmine in action, has a brief duration 10-30 min, suitable as a diagnostic agent for myasthenia gravis and for postoperative decurarization. Tacrine: It is a lipophilic acridine compound which interacts with ChE in a manner analogous to edrophonium. It crosses blood-brain barrier and has a longer duration of action. Donepezil: Another centrally acting anti AChE that has produced cognitive and behavioral improvement in AD. It is long acting and suitable for once daily administration. 