Which of the following sequences is correct in a nucleic acid?

• A
  Phosphate $\rightarrow$ Base $\rightarrow$ Sugar
• B
  Sugar $\rightarrow$ Base $\rightarrow$ Nucleotide
• C
  Base $\rightarrow$ Sugar $\rightarrow$ Phosphate
• D
  Base $\rightarrow$ Phosphate $\rightarrow$ Sugar