The correct option is B A, B, C and D
Nutrition is the process of obtaining and utilizing food for growth and to maintain life.
Saprophytes are organisms (plant, fungus or microbes) that live on dead or decaying organic matter.
Heterotrophs are organisms that are dependent on complex organic substances for nutrition because they cannot synthesize its own food. For example, animals and fungi.
Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments like nitrogen-fixing bacteria, which are capable of transforming atmospheric nitrogen into fixed nitrogen.
Therefore, the correct answer is option C.