The correct option is A Auxotroph
The wild type cells/individuals that are capable of utilizing certain nutrients or synthesizing certain compounds and does not require any additional organic nutrients as growth supplements are called as prototrophs. Auxotrophs are the mutant cells that are incapable of utilizing certain nutrients or synthesizing certain compounds and hence they can grow on minimal media plus the specific growth supplement for which they are mutant. For example, a wild type bacteria capable of utilizing lactose as a nutrient source is prototroph (lac+) while its auxotroph would be unable to utilize lactose is denoted (lac-). Autotrophs are the organisms that can synthesize their own complex organic food using the simpler substances that are found in their surrounding. Green plants synthesize their food in presence of water, sunlight, mineral and carbon dioxide gas and, hence, are the autotrophs. In question, mutant micro-organism is unable to synthesize a compound required for its growth but is able to grow if the compound is provided thus it is an auxotroph.