Consider a production line with five stations. The first station can process a unit in 8 minutes. The second station has two identical machines, each of which can process a unit in 18 minutes (each unit only needs to be processed on one of the two machines). The third station can process a unit in 4 minutes. The fourth station has two different machines, one can process a unit in 5 minutes, and the other one can process a unit in 9 minutes (each unit needs to be processed on both machines). The fifth station can process a unit in 10 minutes. Which station is the bottleneck station?
a) Station 1
b) Station 2
c) Station 3
d) Station 4
e) Station 5
Answer: e) Station 5