Read the following statements and select the correct ones.
(i) A given species may occupy more than one trophic level in the same ecosystem at the same time.
(ii) Productivity of an aquatic ecosystem is less than that of a terrestrial ecosystem.
(iii) Producers constitute the first trophic level of a detritus food chain.

A) i and ii
B) ii and iii
C) i and iii
D) i, ii and iii

Options

A. I and ii
B. ii and iii
C. I and iii
D. I,iiand iii

Explanation

To solve the question, we need to analyze each of the statements provided and determine which ones are correct.

### Step-by-Step Solution:

1. **Analyze Statement (i)**:
- The statement claims that a given species may occupy more than one trophic level in the same ecosystem at the same time.
- This is true. For example, humans can be primary consumers when they eat plants and secondary consumers when they eat animals. Therefore, this statement is correct.

2. **Analyze Statement (ii)**:
- The statement claims that the productivity of an aquatic ecosystem is less than that of a terrestrial ecosystem.
- This is also true. Although aquatic ecosystems cover a larger area (70% of the Earth), terrestrial ecosystems typically have higher productivity due to greater plant density and resource availability. Thus, this statement is correct.

3. **Analyze Statement (iii)**:
- The statement claims that producers constitute the first trophic level of a detritus food chain.
- This is false. In a detritus food chain, the first trophic level is occupied by primary detritivores or decomposers that feed on decomposed organic matter, not producers. Therefore, this statement is incorrect.

### Conclusion:
- Based on the analysis, the correct statements are (i) and (ii).
- Therefore, the correct option is **A) i and ii**.