B - They have different arrangements of atoms.
Mosses,ferns and thallophytes
The RNA codon will be GAU, pairing Cytosine-Thymine-Adenine DNA codon with Guanine-Adenine-Uracil RNA codon. This codon is the Amino Acid, Aspartic Acid. In this codon we see Uracil which is the counterpart of Thymine in the RNA.