The correct option is B a - 3, b - 2, c - 1, d - 2, e - 3
Ecosystem services refers to the products of ecosystem processes that have been linked directly to the benefit of human well-being. Such services include purifying the air, providing water and food by maintaining the nutrient cycle, pollination of crops, soil formation, regulation of droughts, floods, aesthetic beauty and recreation.
Robert Constanza proposed an idea to quantify the ecosystem services with a workshop titled ‘The Total Value of the World’s Ecosystem Services and Natural Capital’. It was held in June, 1996.
The value is estimated to be in the range of US $16−54 trillion per year, with an average of US $33 trillion per year.
Climate regulation - ~ 6%
Climate regulation includes the processes related to the greenhouse effect, the ozone layer, atmospheric chemical composition, precipitation, air quality, moderation of temperature and weather patterns. It is an ecosystem service and the cost of climate regulation is around 6%.
Nutrient cycling - <10%
Movement of essential elements or nutrients through various biotic and abiotic components of the ecosystem is called biogeochemical cycles or nutrient cycles. Nutrient cycling is an ecosystem service and the contribution of nutrient cycling in the total cost of ecosystem services is less than 10%.
Soil formation - 50%
The combination of natural processes which results in the formation of soil is called soil formation or pedogenesis. It is an ecosystem service and accounts for approximately 50% of the ecosystem services out of total cost of ecosystem services.
Recreation - <10%
All the activities like swimming, meditation, enjoying the beauty of nature etc., people choose to refresh their bodies and minds include recreation. It is an ecosystem service and the contribution of recreation in the total cost of ecosystem services is less than 10%.
Habitat for wildlife - ~ 6%
A habitat is a place where an organism lives. It is provided by its ecosystem and the cost of wildlife habitat is around 6%.
Hence the correct option is
c. a - 3, b - 2, c - 1, d - 2, e - 3