The correct option is B protista
Chrysophytes, euglenoids, dinoflagellates and slime moulds are included in the kingdom protista. This kingdom includes all single-celled eukaryotes.
R.H. Whittaker proposed a five kingdom classification in which Protista is a kingdom which comprises organisms which are unicellular but eukaryotic organisms. Its members may be autotrophic or heterotrophic.
Primarily these are aquatic. Protista kingdom has been divided into chrysophytes, euglenoids, dinoflagellates and slime moulds. So, the correct answer is 'Protista'.