The table shows all of the possible outcomes when flipping a coin twice. Which of the following statements must be true?
First Flip Second flip
H H
H T
T H
T T
a. The probability that two flips will have at least one tail is 1/2
b. The probability that two flips will have the same outcome is 1/2
c. The probability of getting exactly two heads is higher than the probability of getting exactly two tails
d. The probability of getting exactly one head and one tail is higher than the probability of getting at least one head