Answer is
A) Electrón trasport chain
Ribozymes are biochemically too complex to have ever produced themselves naturalistically. They are an intermediate cellular functioning assembly that cannot survive on its own and they are too restrictive in function to enable metabolism and reproduction at the level of criticality to be considered plausible for life.
Their simplicity relative to RNA and DNA make them an attractive possibility, but they are not strategic enough, robust enough or in any producible using naturalistic processes.
The correct answer is: desertification.
Desertification is a process in which a land which was not a desert before, becomes one. This process can include drying out- through for example loss of water source, such as river diversion- and the loss of vegetation.
Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water
Other answers:
Overpopulation.
Pollution.
Global Warming.
Climate Change.
Genetic Modification.
Ocean Acidification.
Water Pollution.
Deforestation.
Hardness is the answer I believe
