The correct answer is - b. make their own food.
The plants are differing from most of the other organisms in that that they produce their own food. In order to produce their own food, the plants use the sunlight, carbon dioxide, water, and nutrients from the soil. They manage to perform a process called photosynthesis in which they manage to turn those things into sugars, thus create their own food. That makes the plants producers, which puts them on the bottom of the food chain, meaning they are the basis and most important part of the ecosystems in which they exist.
