Answer:
option C
Step-by-step explanation:
given,
Q = +3.2 x 10⁻¹⁹ C
E = 5.0 X 10⁵ V/m
B = 0.80 T
ion's acceleration is zero
when acceleration is zero the magnitude of both the forces becomes equal.
q E = q V B
v =

v=

v = 6.25 × 10⁵ m/s ≈ 6.3 × 10⁵ m/s
hence, the correct answer is option C