Please answer the following question,..,

Dear student,
Please find below the answer:

The labeled parts are as follows:
A- Nucleolus (non-membrane bound structure within the nucleus).
B- Chromatin (a combination of DNA and protein that makes up the chromosomes in the nucleus).
C- Nuclear envelope (the double membrane surrounding the nucleus).
D- Nucleoplasm (a highly viscous liquid that is present in the nucleus).

Hope this clears your doubt.
Regards.