What velocity should a 1 : 25 model of the ship be towed?

Question

A ship whose full length is 100 m is to travel at 10 m/s For dynamic similarity, with what velocity should a 1 : 25 model of the ship be towed?            

a. 2 m/s                        b. 10 m/s

c. 25 m/s                      d. 250 m/s