Diamond Has an Index of Refraction of 2 $\degree$ B)488 $\degree$ C)155 $\degree$

Multiple Choice

Diamond has an index of refraction of 2.419.What is the critical angle for internal reflection inside a diamond that is in air?

A) 24.4 $\degree$
B) 48.8 $\degree$
C) 155 $\degree$
D) 131 $\degree$