Which of these statements about nucleosomes are correct?

a. The histones H2A, H2B, H3, and H4 make up the nucleosome octamer that binds DNA.
b. Most histones are small (less than 150 amino acid residues), basic proteins rich in Lys and Arg.
c. DNA binding to histones has the same effect as positive supercoiling.
d. Degradation of linker DNA yields DNA fragments of about 200 bp.
e. Partial enzymatic digestion of chromatin results in DNA fragments of about 103 bp.