Volume and surface area II

This task is about volume and surface area.
This shape is made up of four cubes, all the same size, glued together.
Each cube has sides of 5 cm.
a) If calculated correctly, which expression gives the volume of one cube?
  (A)   4 × 4 × 4    
(B)   5 × 5 × 5    
(C)   6 × 6 × 6    
(D)   4 × 5 × 6

(E)   None of these. The correct expression is __________
 
b) What is the total volume of the four cubes?
  (A)   256 cm3    
(B)   480 cm3    
(C)   500 cm3    
(D)   864 cm3

(E)   None of these. The volume is __________  cm3
 
c) If calculated correctly, which expression gives the area of one face of one cube?
  (A)   1 × 3 × 5    
(B)   1 × 6 × 5    
(C)   1 × 5 × 5    
(D)   6 × 5 × 5

(E)   None of these. The correct expression is __________
 
d) What is the surface area of the six faces of one cube?
  (A)   90 cm2    
(B)   150 cm2    
(C)   180 cm2    
(D)   900 cm2

(E)   None of these. The surface area is __________ cm2