The sequence of subunits in the DNA "backbone" is

A) - base- phosphate- base- phosphate- base- phosphate- .
B) - phosphate- sugar- phosphate- sugar- phosphate- sugar- .
C) - base- phosphate- sugar- base- phosphate- sugar- .
D) - sugar- base- sugar- base- sugar- base- sugar- base- .
E) - base- sugar- phosphate- base- sugar- phosphate- .