The Curve Y = X $3$ +X $2$ - X Has Two Horizontal Tangents

Multiple Choice

The curve y = x $3$ +x $2$ - x has two horizontal tangents. Find the distance between these two horizontal lines.

A) $\frac { 11 } { 9 }$

B) $\frac { 22 } { 27 }$

C) $\frac { 32 } { 27 }$
D) $\frac { 5 } { 3 }$
E) $\frac { 14 } { 9 }$
F) $\frac { 4 } { 3 }$
G) $\frac { 13 } { 9 }$

H) $\frac { 7 } { 3 }$