Chọn phương án C.

Đặt \(u=2x-1\Rightarrow \mathrm{\,d}u=2\mathrm{\,d}x\).

Khi đó $$\begin{aligned}
\displaystyle\int f(2x-1)\mathrm{\,d}x&=\displaystyle\int f(u)\cdot\dfrac{1}{2}\mathrm{\,d}u\\
&=\dfrac{1}{2}\displaystyle\int f(u)\mathrm{\,d}u\\
&=\dfrac{1}{2}F(u)+C.
&=\dfrac{1}{2}F(2x-1)+C.
\end{aligned}$$