In question number 45, what will be the electric field at centre O, if the charge from one of the corners (say A) is removed?
A. `q/(4piepsilon_(0)r^(2))` along OA
B. `(2q)/(4piepsilon_(0)r^(2))` along OB
C. `(q^(2))/(4piepsilon_(0)r^(2))` along OC
D. `(2q)/(4piepsilon_(0)r^(2))` along OA