Minimum number of insertions to add a new level to this tree

Question

Answer 1

I think answer should be option A)3

1.add between 42 to 51 it will split the leaf node and internal node at second level e.g.43
2.then add one more key which split leaf node only and inserted at second level . e.g 41
3.now insert one more which will split at all level e.g. 40

Comments

Answer should be (A) only ,  but can u recheck the insertion  43, 41, 40 in that order. I think It does not work.

& then check with 46 , 56, 53  to see if it works..

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can you please post the pic of solution , how the nodes break

Answer 2

D)

Add data in second last leaf node