A model test is to be conducted for an underwater structure, which is likely to be exposed to strong water currents. The significant forces are known to be dependent on structure geometry, fluid velocity, fluid density and viscosity, fluid depth and acceleration due to gravity. Choose from the codes given below, which of the following numbers must match for the model with that of the prototype
1. Mach number
2. Weber number
3. Froude number
4. Reynolds number
a. 3 alone b. 1, 2, 3 and 4
c. 1 and 2 d. 3 and 4