Consider the following statements (A-D) and select the option which correctly fills the blacks.
A. A group of species belonging to a trophic level that exploits a common resources 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).

Options

A. `{:((i),(ii),(iii),(iv),"(v)"),("Guild","Oxygen","Nitrogen","Light","Rocks"):}`
B. `{:((i),(ii),(iii),(iv),"(v)"),("Guild","Anaerobic condition","Light","Nitrogen","Rocks"):}`
C. `{:((i),(ii),(iii),(iv),"(v)"),("Guild","Anaerobic condition","Phorphorus","Dark","Soil"):}`
D. `{:((i),(ii),(iii),(iv),"(v)"),("Guild","Anaerobic condition","Nitrogen","Light","Soil"):}`

Answer

To solve the question, we need to fill in the blanks (i) to (v) in statements A to D correctly. Let's analyze each statement step by step.

### Step 1: Analyze Statement A
**Statement A:** A group of species belonging to a trophic level that exploits a common resource base in a similar fashion is known as (i).

- **Explanation:** In ecology, a group of species that share the same trophic level and utilize resources similarly is referred to as a "guild."

**Fill in the blank:** (i) Guild

### Step 2: Analyze Statement B
**Statement B:** (ii) reduces decomposition and causes the piling up of detritus.

- **Explanation:** Decomposition requires oxygen. When oxygen is absent, the process of decomposition is hindered, leading to the accumulation of detritus. The condition that reduces oxygen availability is "anaerobic."

**Fill in the blank:** (ii) Anaerobic

### Step 3: Analyze Statement C
**Statement C:** In oceans, productivity is limited by (iii) and (iv).

- **Explanation:** In marine environments, the primary factors that limit productivity are light (due to depth and turbidity) and nutrients, particularly nitrogen.

**Fill in the blanks:** (iii) Light, (iv) Nitrogen

### Step 4: Analyze Statement D
**Statement D:** The largest reservoir of calcium is (v).

- **Explanation:** The largest reservoir of calcium in the environment is found in rocks, particularly limestone, which is composed primarily of calcium carbonate.

**Fill in the blank:** (v) Rocks

### Final Answers
Now, we can summarize the filled blanks:
- (i) Guild
- (ii) Anaerobic
- (iii) Light
- (iv) Nitrogen
- (v) Rocks

### Complete Statements
A. A group of species belonging to a trophic level that exploits a common resource base in a similar fashion is known as **Guild**.
B. **Anaerobic** reduces decomposition and causes the piling up of detritus.
C. In oceans, productivity is limited by **Light** and **Nitrogen**.
D. The largest reservoir of calcium is **Rocks**.