The figure shows four directions for the velocity vector  $\overrightarrow{\mathrm{v}}$ of a positively charged particle moving through a uniform electric field $\overrightarrow{\mathrm{E}}$ (directed out of the page and represented with an encircled dot) and  a uniform magnetic field  $\overrightarrow{\mathrm{B}}$. Of all four directions, which might result in a net force of zero?

The cross product of the velocity and the magnetic field should be in the opposite direction of the electric field.

Such direction is possible when the direction of the velocity is in the negative y-axis direction.

So if the particle having velocity along the negative y-axis may have zero net force acting on the particle.