Total contribution margin less total fixed expenses equals A. sales revenue. B. gross profit. C. contribution margin ratio. D. operating income.

A76-year old female with degenerative joint disease made an appointment with an orthopedic surgeon. the patient stated she has had severe pain in her right knee for six months. she has tried physical therapy and steroid injections but has not had any relief. the surgeon has agreed to schedule a right total knee arthroplasty (knee replacement).