The correct answer is: C. master slave JK flip-flop.
A race around problem is a condition that can occur in some types of flip-flops, where the output can change multiple times in response to a single input change. This can happen when the inputs to the flip-flop are both changing at the same time, and the output can change multiple times before the inputs have a chance to settle.
The master-slave JK flip-flop is a type of flip-flop that is free from race around problem. This is because the master and slave stages of the flip-flop are clocked separately, so the output can only change once per clock cycle.
The T flip-flop and the SR flip-flop are not free from race around problem. This is because the inputs to these flip-flops are directly connected to the output, so the output can change multiple times in response to a single input change.
Therefore, the correct answer is: C. master slave JK flip-flop.