Answer:
The correct option is d.
Step-by-step explanation:
One of the main differences between the eukaryotic cell and the prokaryotic cell is that the eukaryotic cell has a membrane bound nucleus while the prokaryotic cell lacks a well defined nucleus (but instead have nucleoid).
One of the primary functions of the nucleus is that, it houses the chromosomes (in eukaryotes), however, the nucleoid plays a similar role to that in prokaryotes.