Example of a denitrifying bacteria which is as well as a Sulphur oxidizer

Answer: Option D

Thiobacillus is one of the denitrifying bacteria which is as well as a Sulphur oxidizer.
Denitrifying bacteria are the group of microorganisms whose action results in the conversion of nitrates in the soil to free atmospheric nitrogen.
And suphur oxidizers are the microorganisms that produce reduced Sulphur compounds formed as a product of anaerobic heterotrophic respiration with sulphate.