Which one of the following Gram positive organism is most common cause of UTI among sexually active women :
Remember:

MC cause of UTI - E. coli
MC cause of nosocomial UTI - E. coli
MC nosocomial infection - UTI
S. saprophyticus produce UTI characteristically in sexually active young woman
Enterococci and S.aureus cause infections in patients with renal stones or previous instrumentation or surgery.
Staphylococcus epidermidis
Staphylococcus aureus
Staphylococcus saprophyticus
Enterococcus