Simplify the Radical Expression $\sqrt [ 4 ] { 4 }$

Multiple Choice

Simplify the radical expression. $\sqrt [ 4 ] { 4 }$

A) $\sqrt [ 2 ] { 4 }$
B) $\sqrt [ 2 ] { 2 }$
C) $\sqrt [ 2 ] { 200 }$
D) $\sqrt [ 4 ] { 2 }$
E) $\sqrt [ 8 ] { 2 }$