Select the wrong statement. 'Diatomaceous earth' is formed by the cell walls of diatoms. Diatoms are microscopic and float passively in water. The walls of diatoms are easily destructible. Diatoms are chief producers in the oceans.

Diatoms are unicellular algae (eukaryotes) placed under kingdom Protista and serve as main producers in oceans. The cell of diatoms is surrounded by the cell wall, deposited with silica, called as frustules which are composed of two overlapping halves (the epitheca and the hypotheca). Shells of diatoms are highly resistant to decomposition due to the presence of silica and are deposited in ocean beds leading to the formation of the diatomaceous earth. The gliding movement of floating diatoms is a passive process, facilitated by secretion of slimy material. Therefore, the correct answer is option D.