Protists are

A. more like other protists than members of other kingdoms.

B. reclassified as scientists learn more about their diversity.

C. members of the plant kingdom.

D. prokaryotes.

Protists are generally grouped together into one biological kingdom not because of inherent similarity among them but rather because they do not fit into any other group, according to current thinking. They do usually consist of unicellular, eukaryotic organisms that do not form tissues, but they do not necessarily have anything in common. The answer is therefore statement (b).