A charged particle is released from the rest in a region of steady and uniform electric and magnetic fields which are parallel to each other. The particle will move in a 

As initially the particle is at rest,

The magnetic field won't act and Electric field gives the particle motion

in direction parallel to $\overrightarrow{E}$

Now when the particle gains motion,

but  v ||E and E || B,

Ultimately v || B,

Hence there will be no magnetic force acting on tje particle to deviate its path,

Hence the Particles motion wil be always straight.

Option $\text{A}$ is the correct answer.