What is the electric flux $\int \vec{E}.d\hat{a}$ 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. A
   $\frac{HQ}{{ϵ}_0}$
2. B
   $\frac{HQ}{4{ϵ}_0}$
3. C
   $\frac{H{ϵ}_0}{4Q}$
4. D
   $\frac{4H}{Q{ϵ}_0}$