Answer: A
Only one node will be there, i.e. (K 20,K 25). After inserting K 15, the node (K 10, K 20) splits and K 15 moves up to form (K 15,K 30).
After K 25 is inserted, K20 moves up to the root & splits up (K15,K30) & it forms (K 20,K 25).
So, after final insertion only (K20,K25) present. So, 1 is the answer.