If $y=(x^{2}1{)}^3(x^2-1{)}^4,$ then $\frac{dy}{dx}$ equals

a$.6x(x^{2}1{)}^2(8x)(x^2-1{)}^3$

b$.3(x^{2}1{)}^2(x^2-1{)}^{4}4(x^2-1{)}^3(x^{2}1{)}^3$

c$.6x(x^{2}1{)}^2(x^2-1{)}^{4}8x(x^2-1{)}^3(x^{2}1{)}^3$

d$.3(x^{2}1{)}^{2}4(x^2-1{)}^3$

Clear my choice