This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid & Electrolyte, Subject name: Surgery
In fluid replacement following a 20% BSA burn, the fluid requirement for the initial 24-hour period is dependent on which of the following? 
Select and explain. 
A. Patient's weight, B. Serum Na, C. CO level, D. Acid base status
A: Patient's weight
Answer: A: Patient's weight 
Explanation: In burns, the Parkland formula is used to calculate initial fluid management. Fluid requirement =4xweight(kg)x% second and third degree BSA. Half this volume is given over the first 8 hours from time of the burn and the other half over the next 16 hours. After the initial 24-hour period, clinical parameters are used to guide fluid management.