Nucleosome core is made of
H1, H2A, H2B & H3
H1, H2A, H2B & H4
H1, H2A, H2B, H3 & H4
H2A, H2B, H3 & H4
As we have discussed in Packaging of DNA Helix in Eukaryotes -
Core histones are H2A, H2B, H3, and H4, where two H3/H4 dimers (H3 and H4 bound together) and two H2A/H2B dimers (these two bound together) form the histone octamer. DNA wrapped around the octamer forms the nucleosome.
Hence, the correct option is (d).