The correct option is: (d) nuclear membrane
Explanation:
All single-celled eukaryotes are placed under protista. Phylogenetically the kingdom Protista acts as a connecting link between the prokaryotic Kingdom - Monera and the complex multicellular Kingdoms - Fungi, Plantae and Animalia.
Being eukaryotes, the protistan cell body contains a well defined nucleus and other membrane-bound organelles. It is surrounded by plasmalemma (cell membrane). Cilia and flagella occur in a number of forms. Nucleus has typical structure - porous nuclear envelope chromatin, nucleolus and nucleoplasm.
Monerans lack nuclear membrane.
