| 下面一道天山数学题，请帮助提示一下解题思路。多谢！
A centain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. if a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of 3 cars?
A: 0
B: 1/9
C: 2/9
D: 1/3
E: 1 | 
