What is the electric flux $\left(\int \vec{E}.d \hat{a}\right)$ through a quarter-cylinder of height $H$ (as shown in the figure) due to an infinitely long line charge along the axis of the cylinder with a charge density of $Q?$
1. $\frac{HQ}{\varepsilon_{0}}$
2. $\frac{HQ}{4\varepsilon_{0}}$
3. $\frac{H\varepsilon_{0}}{4Q}$
4. $\frac{4H}{Q\varepsilon_{0}}$