Match the following and choose the correct option.

	Column I		Column II
(a)	Phosphorus	(i)	Atmosphere
(b)	Carbon	(ii)	Producers
(c)	Goat	(iii)	Rock
(d)	Grasses	(iv)	T2

	(a)	(b)	(c)	(d)
1.	i	iii	iv	ii
2.	iii	i	iv	ii
3.	iii	i	ii	iv
4.	i	ii	iii	iv

Phosphorus is a major constituent of biological membranes, nucleic acids and cellular energy transfer systems. The natural reservoir of phosphorus is rock, which contains phosphorus in the form of phosphates.

Carbon is also a major constituent, which constitutes 49% of dry weight of organisms, which is next only to water. Carbon is present in the atmosphere in the form of carbon dioxide (CO₂).

Goat falls under trophic level 2 (T₂), and is also called a herbivore or primary consumer. Herbivores are those animals that consume green plants (producers) for their source of food.

Grasses are small plants, which are called producers, that make their own food through the process of photosynthesis.