From the following statements, choose the appropriate option:

A structure known as a nucleosome is formed when the positively charged DNA is encircled by the negatively charged histone octamer.

The two turns of DNA are sealed by H1 histone molecules that are located inside the core of the molecule.

A typical nucleosome contains 400 bp of DNA helix.

An additional set of proteins collectively referred to as non-histone chromosomal proteins, are required for the packing of chromatin at a higher level.