Final answer:
The author would most likely agree that only a small number of plants are carnivorous, as they constitute a tiny fraction of the total number of plant species. The correct answer is option c.
Step-by-step explanation:
Based on the comprehension passage provided, the statement that the author would most likely agree with is c. Only a small number of plants are carnivorous. This is because the passage mentions that there are over a quarter of a million plant species, but only about 600 or so are carnivorous, which constitute a very small percentage of the total plant species. Carnivorous plants have evolved unique adaptations to obtain essential nutrients like nitrogen and phosphorus from their prey, due to the nutrient-poor conditions of their habitats such as bogs and swamps.