A temperate grassland biome has a gross primary productivity of 3,480kilocalories/meter2/year and a net primary productivity of 2,000kilocalories/meter2/year. Which of the following is the approximate number of kilocalories/meter2/year available to herbivores in that biome?
a) 200kilocalories/meter2/year
b) 1,480kilocalories/meter2/year
c) 2,000kilocalories/meter2/year
d) 5,480kilocalories/meter2/year

Where are the options?

Mars and earth have quite a few things in common. both are  terrestrial planets, both are located within the sun’s  habitable zone, both have  polar ice caps, similarly  tilted axes, and similar  variations in temperature. and according to some of the latest scientific data obtained by rovers and atmospheric probes, it is now known that mars once had a  dense atmosphere  and was covered with  warm, flowing water.