Tìm họ nguyên hàm của hàm số f (x) = 1/2 căn bậc hai 2x+1

A. $\int \mathrm{f}\left(\mathrm{x}\right)\mathrm{d}\text{x=}\sqrt{2\text{x}+1}\text{+C}$

B. $\int \mathrm{f}\left(\mathrm{x}\right)\mathrm{d}\text{x=}\frac{1}{2}\sqrt{2\text{x}+1}\text{ +C}$

C. $\int \mathrm{f}\left(\mathrm{x}\right)\mathrm{d}\text{x=2}\sqrt{2\text{x}+1}\text{ +C}$

D. $\int \mathrm{f}\left(\mathrm{x}\right)\mathrm{d}\text{x=}\frac{1}{\left(2\text{x}+1\right)\sqrt{2\text{x}+1}}\text{+C}$