In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be a:

Let both fields be along the $z$ -axis: $\vec{E}=E\hat{k}$ and $\vec{B}=B\hat{k}$.The particle is released from rest ($\vec{v}=0$).The magnetic force $\overrightarrow{F_m}=q(\vec{v}\times \vec{B})=0$ initially.The electric force $\overrightarrow{F_e}=q\vec{E}$ will accelerate the particle along the direction of $\vec{E}$ (the $z$ -axis).As the particle gains velocity along the $z$ -axis, $\vec{v}$ remains parallel to $\vec{B}$.The magnetic force remains $q(\vec{v}\times \vec{B})=0$ throughout the motion because the angle between $\vec{v}$ and $\vec{B}$ is $0^{\circ }$.Thus, the particle moves in a straight line under the influence of the electric field only.