Each place to the left is 10 times greater than the place immediately to its right.
A. There are two 4's in a row. 44 <------ I think your first clue is incorrect
B. There is a 5, followed by something, then followed by a 2. 5_2
C. The 6 follows the 2. 5_26
D. 15_26
My guess is the answer is 15426.
I think your first clue is incorrect.