Correct Answer - D
Ciliates differ frorn all other protozaans in having two types of nucloi
These two nuclei are usually of different size, i.e. one is meganucleus and the other is micronuclous. Tho former controls metabolism whereas the latter is concerned with reproductions e.g. paramecium.
In other protozoans, like Amoeba, single nuclous is present which is involved in metabolism and reproduction.
Other options are incorrect because Ciliates use filtre feeding mechanism for obtaining food.
Like other protozoans, they also possess contractile vacuoles. Ciliates use cilia for locomotion.
