A particle of charge q and mass m is subjected to an electric field E=E0(1−ax2) in the x-direction, where a and E0 are constants. Initially the particle was at rest at x=0. Other than the initial position the kinetic energy of the particle becomes zero when the distance of the particle from the origin is : [Main Sep. 04, 2020 (II)]
a. a
b. a2
c. a3
d. a1