Let's first determine how many balloons are left after the 12 that burst.
Initially, there are 272 balloons. After 12 balloons burst, the number of balloons left is: \[ 272 - 12 = 260 \]
Now, we need to divide the remaining 260 balloons evenly into 5 rooms. We do this by dividing 260 by 5:
\[ 260 \div 5 = 52 \]
Thus, the number of balloons in each room is: \[ \text{Answer: } 52 \]
So, the correct answer is A. 52.