Correct option is (D) E along OK
Explanation:
I think the figure is like this. If it is same as you are asking.

As per the question, the ring is conducting. So It is obvious that the total electric field at the centre is zero.
Etotal = 0
So, EAKB + EACDB = 0
or, EACDB = - EAKB
or, EACDB = - E (towards centre along KO)
Or, EACDB = E (Along OK)