Which of the following statements is/are correct?

a. In a grazing food chain, the first level starts with plants as producers and ends with herbivores as consumers at the last level. b. A detritus food chain is based on the decomposition or breaking down of organic wastes and dead matter derived from the grazing food chain. c. In a carnivorous food chain, the first level starts with carnivores as consumers and ends with top carnivores at the last level.