Final answer:
Bacteria that grow in mine drainage at pH 1-2 are known as acidophiles, which are specially adapted to thrive in highly acidic environments. Hence, option (a) is correct.
Step-by-step explanation:
Bacteria that grow in mine drainage at pH 1-2 are considered (option a) acidophiles. These microorganisms thrive in extremely acidic environments, where most other life forms cannot survive. Acidophiles have evolved unique adaptations that allow them to maintain stability as well as function in these harsh conditions.
An example of such extremophiles includes certain species like those of the genus Ferroplasma, which are found in acid mine drainage and can withstand pH values as low as 0-2.9. Acidophilic bacteria like Lactobacillus are also notable for their ability to not just survive, but to also contribute to acidic environments through their metabolic processes.