Figure 1 represents a nucleic acid fragment that is made up of four nucleotides linked together in a chain. The figure presents a single chain of four linked nucleotides. The 5 prime end is indicated at the beginning of the chain, and the 3 prime end is indicated at the end of the chain. Each nucleotide is composed of a pentose sugar, a nitrogenous base bonded to the first carbon of the sugar, and a phosphate group bonded to the fifth carbon of the sugar. Two of the bases are double-ring purines and two of the bases are single-ring pyrimidines. Each phosphate group is shown to be negatively charged. The pentose sugar at the 3 prime end of the chain has two OH groups bonded to it, one each at carbon 2 and carbon 3.
Figure 1. Nucleic acid fragment

Which of the following characteristics of Figure 1 best shows that the fragment is RNA and not DNA?

The 5′ to 3′ orientation of the nucleotide chain

The 5′ to 3′ orientation of the nucleotide chain
A

The identity of each nitrogenous base

The identity of each nitrogenous base
B

The charges on the phosphate groups

The charges on the phosphate groups
C

The type of bond linking the nucleotides together