We Grow Resistant (Str^r)cells to a Concentration of 10⁹ and Plate

Multiple Choice

We grow resistant (Str^r) cells to a concentration of 10⁹ and plate them on a medium with 25 µg/mL gentamicin.Six colonies grow.These cells should be

A) Str^r.
B) Gen^r.
C) Str^r Gen^r.
D) wild-type.
E) Str^r Gen^s.