This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A child is diagnosed to have acute gastroenteritis. The consulting pediatrician wants to send a stool sample to a lab which is 16-18 hours away. Which of the following mediums should he use to send this sample – 
Select and explain. 
A. Charcol cotton bud, B. Carry Blair medium, C. Sterilized jar, D. A medium with high CO2 content
B: Carry Blair medium
Answer: B: Carry Blair medium 
Explanation: In acute gastroenteritis stool culture should be obtained as early as possible.
"Fecal specimens that cannot immediately be plated for culture can be transported to the laboratory in a non-nutrient holding medium such as Carry-Blair to prevent drying or overgrowth of specific organisms".