art $3$ of $3-$ Parallel Plates

A stagnant liquid is contained between tw$$ large, parallel horizontal plates which are separated by a distance, $2$B$.$ At time $t=0,$ the lower plate is set in motion from left to right at a velocity, $V.$ At the same time, the upper plate is set in motion from right to left at a velocity, $2V.$

Question $9$ of $9$

Mark each of the following which would be appropriate spatial boundary conditions to properly model the motion of the fluid between the plates.

A$.$ At $y=0,v_x=v.$

B$.$ At $y=0,v_x=0.$

C$.$ At $y=B,v_x=2V.$

D$.$ At $y=2B,v_x=-2V.$

E$.$ None of the above.