The Lorentz force law is

Initially,

, so the second term inside the parenthesis is

. So, at
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, the particle experiences a force in the direction of the electric field, which gives the particle a velocity in the direction of the electric field. Since

and

are parallel, the second term inside the parenthesis is still

. So, the particle will continue to move in a straight line and not experience any magnetic force. Therefore, answer (E) is correct.