下列计算错误的是 $($ 　　 $)$

A．	${(-3a{b}^2)}^2=9a^2{b}^4$	B．	$-6a^{3}b÷3\mathit{ab}=-2a^2$
C．	${\left(a^2\right)}^3-{(-a^3)}^2=0$	D．	${(x+1)}^2=x^2+1$