A commuter train from Long Island to New York City is scheduled to arrive at 8:07 AM every weekday morning. The probability that the train arrives on time is 0.90. Suppose 20 weekdays are randomly selected. What is the probability that the train will arrive on time on at least 15 days?
a) 0.9890
b) 0.043
c) 0.957
d) 0.0319