The origin of predation ability of Venus flytraps is explained by

Venus flytraps are green plants that are found in a habitat where nitrogen is not freely available in the soil. These plants have modified leaves and they have a scent that attracts insects. Trigger hairs on the leaf surface are sensitive to touch and detect the arrival of an insect causing the leaf to fold. The interlocked insect is then digested by enzymes of the leaf. The insects serve as a source of nitrogen for these plants and the modification imparts the survival advantage to the plants under nitrogen-deficient soil. Thus, the correct answer is option A.