The lines in the text that support the title ‘The Ailing Planet’ are

a. The earth’s vital signs reveal a patient in declining health.

b. In large areas of the world, human claims on the systems of fisheries, forests, grasslands, and croplands are reaching an unsustainable level, a point where their productivity is being impaired. When this happens, fisheries collapse, forests disappear, grasslands are converted into barren wastelands, and croplands deteriorate.

c. The world’s ancient patrimony of tropical forests is now eroding at the rate of forty to fifty million acres a year, and the growing use of dung for burning deprives the soil of an important natural fertilizer

d. There can be no doubt that the growth of world population is one of the strongest factors distorting the future of human society.