Nuclease-hypersensitive sites in the chromosomes are sites that appear to be (A) H2 and H4 histone free (B) H1 and H2 histone free (C) H3 and H4 histone free (D) Nucleosome free

Answer: (D) Nucleosome free
Nuclease-hypersensitive sites are regions of the chromosome that are more accessible to nucleases due to the absence of nucleosomes, indicating that they are nucleosome-free. This accessibility is often associated with active regulatory regions.