The correct option is
A Photosynthesis
Correct answer
Option A- Photosynthesis
- Plants acquire their energy from the sun, which is then used by them to produce food through a process known as photosynthesis.
- Due to this, plants are referred to as producers.
- They prepare their own food and do not rely on other creatures for nutrition.
- As a result, they are classified as members of the first trophic level of the food chain and the food chain starts with photosynthesis.
Incorrect options
- option B - Plants use the sugars created during photosynthesis, along with oxygen, to produce energy for growth and respiration, hence, photosynthesis needs to occur first in order for plants to respire.
- option C - When a plant, animal, or insect dies, it is broken down into tiny particles that form part of the soil. This is referred to as decomposition. So, it always occurs at the last stage.
- option D - The purpose of nitrogen-fixing bacteria is to provide plants with a fertilizer that they cannot get from the air.
Hence the correct answer is A- The food chain starts with Photosynthesis