A thin conducting ring of radius R is given a charge +Q. The electric field at the centre O of the ring due to the charge on the part AKB of C the ring is E. The electric field at the centre due to the charge on the part ACDB of the ring, (Fig. 2.101) is : 

• A

  3 E along OK

• B

  3 E along KO

• C

  E along OK 

• D

  E along KO