Primary productivity does not depend on:

The correct answer is Option (2) → Secondary consumers

Option (1) Plant species — Depends on it.

Option (2) Secondary consumers — Does not depend on it. NCERT names the plant species of the area, environmental factors, availability of nutrients and photosynthetic capacity of plants. Secondary consumers feed higher in the food chain and are not among these factors.

Option (3) Environmental factors — Depends on it.

Option (4) Nutrients availability — Depends on it.

NCERT Extract:
Productivity – “… Primary productivity depends on the plant species inhabiting a particular area. It also depends on a variety of environmental factors, availability of nutrients and photosynthetic capacity of plants. Therefore, it varies in different types of ecosystems. The annual net primary productivity of the whole biosphere is approximately 170 billion tons (dry weight) of organic matter.”