The correct option is C Pistia
Pistia is an aquatic plant, more specifically a hydrophyte. In hydrophytes, the roots are insignificant since these plants absorb water mostly though their leaves.
Pistia is a genus of aquatic plant in the arum family Araceae. It is a perennial monocotyledon with thick, soft leaves that form a rosette. It floats on the surface of the water, its roots hanging submersed beneath floating leaves. Pistia is a hydrophyte, where absorption of water by roots is insignificant.
Hence, the correct answer is option B.