Consider the sequence 1 to 10 for insertion. Since the order is 4, the max number of keys would be 3 and min number of keys would be 1.
Now, first three insertions will not cause a split: 1/2/3
The fourth insertion causes split:
Now, the fifth and sixth insertions will not result in a split:
Now, the seventh insertion will create a split:
1/2 4/5 7
Now, eight and ninth insertions will not create a split:
1/2 4/5 7/8/9
Now, the tenth insertion causes split :
1/2 4/5 7/8 10
We have 3 splits. But, this is not the maximim number of splits. For max number of split we need insert along the leaves which have the majority elements, shown below by other users. Therefore 3 is not the right answer.