A Right Triangle Is Submerged Vertically with One Side Parallel $\rho$

Multiple Choice

A right triangle is submerged vertically with one side parallel to the surface in a liquid of density $\rho$ . The triangle has a leg that is 12 m long located at the surface and a leg 12 m long straight down. Find the force exerted on the triangular surface, in terms of the density. Neglect the effect of the atmosphere above the liquid.

A) 288 $\rho$ N
B) 864 $\rho$ N
C) 576 $\rho$ N
D) 48 $\rho$ N
E) 36 $\rho$ N