The correct option is B A coin is tossed.
Experimental probability is based on the data which is obtained after an experiment is carried out.
Theoretical probability is based on what is expected to happen in an experiment, without actually conducting it.
In option (a.), we have
A coin is tossed 20 times and it is recorded that heads occurred 8 times and tails occurred 12 times.
This is an example of Experimental probability.
In option (b.), we have
A coin is tossed.
P(Head)=12
P(Tail)=12
This is an example of theoretical probability.
Therefore, option (b.) is the correct answer.