Which one of the following numbers is smallest in value?
A $\quad \log _ { 2 } 7$
B $\left( 2 ^ { - 3 } + 2 ^ { - 2 } \right) ^ { - 1 }$
C $2 ^ { ( \pi / 3 ) }$
D $\frac { 1 } { 4 ( \sqrt { 2 } - 1 ) ^ { 3 } }$
E $\quad 4 \sin ^ { 2 } \left( \frac { \pi } { 4 } \right)$