You are searching for a strain of bacteria that can grow on the antibiotic kanamycin, whereas most bacteria cannot grow. You are also looking to see if this bacteria can utilize lactose, if it can use lactose as a carbon source the bacteria will turn blue. If the bacteria cannot use lactose, they will be white. You make your media and you add kanamycin and a dye that turns the bacteria blue if lactose is used.

For this media kanamycin alone is
a. Differential
b. Selective
c. Selective-differential