In Whittaker's classification, unicellular and eukaryotic organisms are grouped under:
Correct option is C. Protista
In Whittaker's five kingdom classification, the kingdoms Monera and Protista include unicellular organisms. Kingdom Monera includes all prokaryotic unicellular organisms like bacteria and archaebacteria, while kingdom Protista includes all eukaryotic unicellular organisms like Amoeba, Euglena, etc. Kingdom Fungi includes eukaryotic organisms. Most of them are multicellular, except yeast, which is unicellular. Phylum Porifera comes under the kingdom Animalia. The phylum includes multicellular animals.
So, the correct answer is C.