Under the electron microscope chromatin appears to have a string of bead-like structures called nucleosomes. The adjoining diagram shows one such unit. The labeled parts $$1$$ and $$2$$ are its important constituents made up of a total of $$5$$ components. Choose the correct option showing the correct sequence of the $$5$$ component units included in the labeled parts $$1$$ and $$2$$.

A

H1, H2a, H2b, H3 and H4

B

H1, H2b, H3b and H4

C

H2a, H2b, H3, H4 and H1

D

H1, H2, H3a, H3b and H4