Cho khai triển ...

Câu hỏi: Cho khai triển $$\begin{gathered} P\left(x\right)=\left(1+x\right)\left(1+2x\right)...\left(1+2017x\right) \\ =a_0+a_{1}x+...+a_{2017}{x}^{2017} \end{gathered}$$.

A. ${\left(\frac{2016.2017}{2}\right)}^2$ 

B. ${\left(\frac{2017.2018}{2}\right)}^2$

C. $\frac{1}{2}.{\left(\frac{2016.2017}{2}\right)}^2$

D. $\frac{1}{2}.{\left(\frac{2017.2018}{2}\right)}^2$