$f(x)=x^{4}-x^{2}+\frac{1}{4}$ এবং $g(x)=\sqrt{x+1}$ হলে, $\text { fog }(x)=$ কত?

$\left(x-\frac{1}{2}\right)^{2}$

$\left(x+\frac{1}{2}\right)^{2}$

$(2 x+1)^{2}$

$(2 x-1)^{2}$