Answer:
B) 9
Explanation:
When looking in both the horizontal and vertical direction of the missing space, we can see that the difference between the two numbers, 12 and 15, is 3.
15 - 12 = 3
Using this, we can see that each space on the second row and second column change by 3. Therefore, when looking at the missing space in the sequence, we can figure out that it is 9 by adding 3 to 6.