A small metal block (shaded block) is released from rest at the level of the top dashed line. It either falls or slides on a frictionless incline to the level of the bottom dashed line (dotted block). For which choice is the speed of the block greatest at the bottom dashed line?

a) Falling

b) Sliding on the 30° incline

c) Sliding on the 60° incline

d) Sliding on either incline

e) All three choices result in the same speed