This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lab Investigations, Subject name: Microbiology
[{'content': 'CLED agar is preferred to MacConkey in the processing of urinary samples because : \nSelect and explain. \nA. It suppos both Gram positive and Gram negative organisms, B. It prevents swarming of Proteus, C. The growth can be seen in 4 hours, D. Klebsiella and E.coli can be differentiated easily', 'role': 'user'}, {'content': 'Answer: A \nExplanation: CLED (Cysteine Lactose Electrolyte Deficient) medium Non-selective medium on which both Gram positive and Gram negative bacteria can grow. MacConkey Mildly selective medium for Gram negative. Most Gram positive is inhibited. CLED agar is hence preferred over MacConkey in the processing of urinary samples. Both media inhibit swarming of Proteus. Since both contain lactose, both are differential media, i.e-LF and NLF can be differentiated.', 'role': 'assistant'}]