Consider the following statements (A - D) and select the option which correctly fills the blanks.

A. A group of species belonging to a trophic level that exploits a common resource base in a similar fashion is known as ____(i)____.

B. _____(ii)_____ reduces decomposition and causes the pilling up of detritus.

C. In oceans, productivity is limited by _____(iii)_____ and _____(iv)_____.

D. The largest reservoir of calcium is ____(v)____.

	(i)	(ii)	(iii)	(iv)	(v)
1	guild	Oxygen	nitrogen	light	rocks
2	guild	Anaerobic condition	light	nitrogen	rocks
3	guild	Aerobic respiration	phosphorus	dark	soil
4	guild	Anaerobic respiration	nitrogen	light	soil