• (A) They have remained in that particular stage of evolution as living fossils, a link between autotrophs and heterotrophs
• (B) Their growth in shady and dark places does not allow them to undertake sufficient photosynthesis and thus, they depend on insects for nutrition
• (C) They cannot synthesise certain vitamins themselves and depend on the insects digested by them
• (D) They are adapted to grow in nitrogen deficient soils and thus, depend on insects for sufficient nitrogenous nutrition