A Layer of Water (N = 1 $\degree$ B)78 $\degree$ C)66 $\degree$ D)58 $\degree$

Multiple Choice

A layer of water (n = 1.333) floats on carbon tetrachloride (n = 1.461) contained in an aquarium.To the nearest degree,what is the critical angle at the interface between the two liquids?

A) 88 $\degree$
B) 78 $\degree$
C) 66 $\degree$
D) 58 $\degree$
E) 43 $\degree$