设函数 $f_1\left(x\right)=x^2$， $f_2\left(x\right)=2(x-x^2)$, $f_3\left(x\right)=\frac{1}{3}\left|\sin 2\pi x\right|$， $a_i=\frac{i}{99},i=0,1,2,...,99$，记 $I_k=\left|f_k\left(a_1\right)-f_k\left(a_0\right)\right|+\left|f_k\left(a_2\right)-f_k\left(a_1\right)\right|+...+\left|f_k\left(a_{99}\right)-f_k\left(a_{98}\right)\right|$, $k=1,2,3$则(      )

$I_1<I_2<I_3$

$I_2<I_1<I_3$

$I_1<I_3<I_2$

$I_3<I_2<I_1$