If a chord of the parabola $y^2=4x$ passes through its focus and makes an angle $\theta$ with the $X-axis,$ then its length is

Question

\[\begin {array} {1 1} (a)\;4 \cos ^2 \theta & \quad (b)\;4\; \sin ^2 \theta \\ (c)\;4\; cosec ^2 \theta & \quad (d)\;4 \sec^2 \theta \end {array}\]