Why are people concerned about the sustainability of fossil fuels? explain

People are concerned because humans are pretty dependant on fossil fuels! Did you know 70% of Chinas electricity is Generated from Coal? Thats how dependant we are on Fossil fuels in just one short example,however Fossil fuels aren't bad they are great energy sources! :D Hope that helped ~Feel Free to mark brainliest~

the wrong statement is - c. a desert had more biodiversity than a marsh.

the deserts are one of the places of the planet where there's the least biodiversity. the reasons for that are the climate and the lack of food sources, which hampers both the number of the species that can survive in it, and the number of the individuals in the species itself.

the marshes, on the other hand, are places where there's perfect conditions for lots of organisms to thrive. the temperature is moderate and nice, the amount of water and the food sources are on a high level, so there's an abundance of both plant and animal life in them.