In counterfort type retaining walls_____________?

1. the vertical slab is designed as a continuous slab
2. the heel slab is designed as a continuous slab
3. the vertical slab is designed as a cantilever
4. the heel slab is designed as a cantilever
The correct answer is?
A. (1) and (ii)
B. (1) and(4)
C. (2) and (3)
D. (3) and (4)