Step 1: Bernoulli's principle underlies hydrodynamics.
Step 2: Helmholtz is linked to acoustics, and Kepler to mechanics, not fluid dynamics.
Step 3: Prandtl's boundary-layer theory founded modern aerodynamics.
Step 4: The correct answer is \[ \boxed{\text{(A)-(I), (B)-(III), (C)-(II), (D)-(IV)}} \]