Bacteria provides a valuable clue to the origin of life on earth. which of these is the most likely process by which bacteria was formed? a) appearance of new plants b)adaption of living things c) geological transformation of earths crustd) chemical transformation of non-living matter

None of the above. There are no naturalistic processes that ever produced more than the simplest abiotic chemical assemblies, e.g., simple amino acids, formaldehyde, simple sugars, what entropy would allow through stochastic and random interaction of elements.

It is not definite, but eukaryotes, prokaryotes, and archaea are believed to be the first organisms and were created to begin the process of bioforming the Earth: changing the atmospheric content, processing and removing for collection the poisonous elements, creating organic material that became the food source for eventually larger, more complex organisms. This took billions of years and was required because non-organic processes - tides, wind, volcanoes, plate tectonics, meteor impacts, lightening, etc., are not correct processes to ultimately transform the Earth for, eventually, us.