Water is falling from the top of a high water fall. On falling

A) it evaporates
B) it freezes
C) there is no change in its condition
D) it gets slightly warmed up

When water falls from a height, the potential energy in it gets converted into kinetic energy which increases the inter molecular motion and thus increases its internal energy and this rises the temperature.
So the answer's D). It get slightly warmed up.

Believe it or not, all four are possible depending on the temperature of the water W, the temperature of the air A, and the dew point of the air D. During the fall the water is suddenly put in close contact with the air and this can bring about any number of interesting changes.

(A) If D0(C), then the water will evaporate into the air but remain in liquid form

(B) If A<0(C) then the water can freeze on its way down. Note that some combinations of A merely near 0C but D well below 0C could also result in freezing due to evaporative cooling leading to the phase change.

(C) If A=W=D then the water remains in equilibrium with the air all the way down -- no change

(D) If D>W then moisture will condense onto the water, causing it to heat up

It evaporates as it falls. As water evaporates it cools down. Probably not enough to freeze.

It'll largely just evaporate, that's why waterfalls often have large clouds of mist around them.

C) there is no change in its condition....I believe. It should just turn into mist, but that's not water vapor nor ice.