The pitch of the double-stranded B-DNA helix is

The correct option is D

Both A and C

The correct option is D

Explanation of the correct option:

1. A "double helix" is the name for the structure formed by DNA and other double-stranded nucleic acids.
2. The most common DNA conformation is thought to be B-DNA, in which the chains twist to the right and up around the front of the helix's axis.
3. 34 Angstroms is the pitch of the B-DNA strand.
4. A 34 Angstrom is equal to 3.4 nanometers.

Final answer: The pitch of the double-stranded B-DNA helix is 34 Angstrom or 3.4 nm.