The probability of winning a certain game is 0.5. If at least 70 percent of the games in a series of n games are won, the player wins a prize. If the possible choices for n are  n=10, n=20, and n=100  which value of n should the player choose in order to maximize the probability of winning a prize? 
选项为:A:n=10 only  B:n=20 only  C:n=100 only  D:n=10 or n=20 only;~the probabilities are the same.  E:n=10 or n=20 or n=100; the probabilities are the same.  请回答其中一个选项.