A Catheterized Urine Was Processed and the Resulting Culture Sheep

A catheterized urine was processed and the resulting culture sheep blood and MacConkey agar plates are provided. How do you account for the difference in the colony counts between the two agar plates?

A) The urine loop used to inoculate the blood agar was inserted into the urine at a 90° angle.
B) The urine sat at room temperature prior to processing, allowing the organisms to multiply.
C) The urine loop was not redipped into the urine prior to inoculation of the MacConkey agar.
D) Two different sizes of calibrated loops were used for inoculation.