Final answer:
The traits of an organism are determined by the sequence of nitrogen bases in DNA, making option C the correct answer to the student's question.
Step-by-step explanation:
In DNA, the traits of an organism are determined by the sequence of nitrogen bases. These nitrogen bases are adenine (A), thymine (T), cytosine (C), and guanine (G), which pair together to form the double helix structure of DNA. The sequence of these bases encodes the genetic instructions needed to develop and direct the activities of every organism. The correct answer to the student's question is option C, the sequence of nitrogen bases.
The number of sugars, amount of adenine, and strength of hydrogen bonds while important to the structure and stability of DNA, do not determine traits. Traits are inherited through the specific combination of genes, which are sequences of these nitrogenous bases within the DNA molecule.