The correct option is C 8
The total number of layers of cubes is 4.
Total number of cubes in the top layer = 1
Total number of cubes in the second layer = 1
Total number of cubes in the third layer = 2
Total number of cubes in the lower layer = 4 (1 is hidden)
So total number of cubes
= 1 + 1 + 2 + 4 = 8.