An `alpha`-particle is describing a circle of radius 0.45 m in a field of magnetic induction `1.2 "weber/m"^(2)`. The potential difference required to accelerate the particle, (The mass of a-particle is `6.8 × 10^(-27)` kg and its charge is `3.2 xx 10^(-19)` coulomb.) will be —
A. `6 xx 10^(6)V`
B. `2.3 xx 10^(-12) V`
C. `7 xx 10^(6)V`
D. `3.2 xx 10^(-12)V`
