Aclient with a tentative diagnosis of myasthenia gravis is admitted for a diagnostic workup. myasthenia gravis is confirmed by: a) brudzinski's sign. b) a positive sweat chloride test. c) a positive edrophonium (tensilon) test. d) kernig's sign.

a positive edrophonium (Tensilon) test.

A positive edrophonium test confirms the diagnosis of myasthenia gravis. After edrophonium administration, most clients with myasthenia gravis show markedly improved muscle tone. Kernig's sign and Brudzinski's sign indicate meningitis. The sweat chloride test is used to confirm cystic fibrosis.