Answer:
Explanation:
Over the past 250 year or two and a half centuries fossil fuels have been burnt at a very fast rate to meet the various human needs. These fossil fuels contains huge amount of carbon dioxide. And when these fossil fuels are burnt in power factories, power plants, cars etc. carbon moves from the fossil to the atmosphere. And since carbon dioxide is a greenhouse gas it traps more heat and hence there is a global temperature rise.
It is estimated that every year almost five and a half billion tons of carbon is released by burning fossil fuels. And since this amount of carbon dioxide is very huge for plants to convert all of them into oxygen via photosynthesis it leads to disbalancing in the carbon cycle that is more carbon dioxide is produced than the amount can be utilized which finally leads to rise in Earth's temperature as all of the extra carbondioxide ends up in Trapping more sun light.
Sugars are molecules that have a 1:2:1 c:h:o and are called carbohydrates.
The most important thing for the survival of the rapidly growing population in the capital city is the food. The food is the very basic need of an individual. The other facilities needed by the population, such as recreational spots, better communication and transportation systems are all secondary to the food. The lack of food will lead to starvation and ultimately death.
Hence, the correct answer is option (b) - structures for growing food in or near cities.
