Help pls!! acceleration:

a) the rate of change of position

b) acceleration caused by the force of gravitation

c) the rate of change in velocity; speeding up, slowing down, or changing direction

d) for every action force, there is an equal and opposite reaction force

Consider a production line with five stations. station 1 can produce a unit in 9 minutes. station 2 can produce a unit in 10 minutes. station 3 has two identical machines, each of which can process a unit in 12 minutes (each unit only needs to be processed on one of the two machines. station 4 can produce a unit in 5 minutes. station 5 can produce a unit in 8 minutes. which station is the bottleneck station?