Q. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal

• (A) Ratio of inertial force to force due to viscosity
• (B) Ratio of inertial force to force due to gravitation
• (C) Ratio of inertial force to force due to surface tension
• (D) All the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity