a) Classical. This is because there are 2 sides and 1/2 = 0.50 = 50% is the chance of landing on tails. Classical probability is also known as theoretical probability.
b) Subjective. This is based off John's belief and his gut feeling. There doesn't seem to be any empirical data to back him up, unless he's looking back at previous semesters.
c) Empirical. When you have a finite set of data and you compute the probability based on it like what we're doing here, we're computing empirical probability. Another example would be that if you flipped a coin 30 times and got 17 heads, then the empirical probability of getting heads is 17/30 = 0.5667 approximately. Note how this is slightly different from the theoretical probability 0.50