Find All Relative Minima of the Given Function $y = x ^ { 4 } - 8 x ^ { 3 } + 16 x ^ { 2 } + 16$

Multiple Choice

Find all relative minima of the given function. $y = x ^ { 4 } - 8 x ^ { 3 } + 16 x ^ { 2 } + 16$

A) $( 0,16 )$
B) $( 2,32 )$
C) $( 4,16 )$
D) $( 0,16 )$ , $( 4,16 )$
E) no relative minima