The acceleration of the charge on the gap faces will cease when the total electric field within the ring becomes zero. For this to happen, the electric field `E_(0)` in the gap is
A. (a) `E_(0) = (abeta)/(delta)`
B. (b) `E_(0) = (2a beta)/(delta)`
C. ( c) `E_(0)` is dependent of `R` for `R gt sqrt((a)/( pi))`
D. ( d) `E_(0)` is independent of `R` for `R gt sqrt((a)/( pi))`