Find $\frac{1}{3}+\frac{1}{15}+\frac{1}{15}+\frac{1}{35}+\frac{1}{63}+\frac{1}{99}$ +....upto n terms

Question

$\begin{array}{1 1} \large\frac{4}{2n-1} \\ \frac{1}{2n+1} \\ \frac{1}{n+1} \\ \frac{n}{2n+1} \end{array}$