An organism which is sensitive to an antibiotic is grown in the lab in a pure culture on a medium with the antibiotic , if we see colonies of the organism growing on the plate then it must have undergone

a. transpoon muagenesis
b. spontaneous mutation
c. natural selection
d. x ray induced mutation

the vp test is used to differentiate

a. gram positive organisms
b. gram negative organisms
c. klebsiella vs enterobacter
d. genus of enterobacteriaceae family