Answer the following question given this paragraph: 

Simple Model of DNA. In this simple model of DNA, each line represents a nucleotide chain. The double helix shape forms when the two chains wrap around the same axis.


Q: What distinctive dna shape forms when the two nucleotide chains wrap around the same axis?

 Choices:

- single spiral

- chain helix

- double spiral

- double helix

A:
double helix
