The least possible value of the gradient of the curve $y = ( 2 x + a ) ( x - 2 a ) ^ { 2 }$ at the point where $x = 1$, as $a$ varies, is A $- \frac { 49 } { 4 }$ B - 8 C $- \frac { 25 } { 4 }$ D $\frac { 7 } { 4 }$ E $\frac { 47 } { 16 }$
& C & 15 & D
The least possible value of the gradient of the curve $y = ( 2 x + a ) ( x - 2 a ) ^ { 2 }$ at the point where $x = 1$, as $a$ varies, is
A $- \frac { 49 } { 4 }$
B - 8
C $- \frac { 25 } { 4 }$
D $\frac { 7 } { 4 }$
E $\frac { 47 } { 16 }$