Determine whether the following probabilities are best categorized as subjective, empirical, or classical probabilities.
a. Before flipping a fair coin, Sunil assesses that he has a 50% chance of obtaining tails.
b. At the beginning of the semester, John believes he has a 90% chance of receiving straight A’s.
c. A political reporter announces that there is a 40% chance that the next person to come out of the conference room will be a Republican, since there are 60 Republicans and 90 Democrats in the room.