In both `DNA` and `RNA`, the heterocyclic base and phosphate ester linkages are at:
A. `C_(5) and C_(2)`, respectively, of the sugar molecule.
B. `C_(2) and C_(5)`, respectively, of the sugar molecule.
C. `C_(1) and C_(5)`, respectively, of the sugar molecule.
D. `C_(5) and C_(1)`, respectively, of the sugar molecule.
