Which description best explains Watson and Crick's DNA model?

A.

DNA is a single–stranded molecule that has nitrogenous bases toward its exterior.

B.

DNA is a double helix made of two strands linked together with hydrogen bonds.

C.

DNA is a double helix that contains nitrogenous bases toward its exterior

You are studying a protein that you call protein x. there is an aspartic acid at a key position in protein x which is important in the folding and stabilization of that protein. if this aspartic acid is changed to a different amino acid, which type of amino acid substitutions is most likely to allow the protein to fold normally?