C.
Biotic mean alive, so we can cut off the first 2 easily. Aquatic birds eat frogs, so that one is safe for now. A decrease in something parasitic usually helps the population, so D is out too. The only one left is C.
I believe it is the first option
Answer:
The correct answer is option - A. 0.
Explanation:
Producers are the organism that produces on their own. They do not depend on other organisms for their nutrition and energy such as green plants. They transfer energy and nutrition.
In the given scenario there is no producer present all are consumers of different levels. Cricket is a primary consumer, a spider is a secondary consumer and bird is the third consumer in this food chain.
Thus, the correct answer is option- A. 0.
Darwin's idea of the survival of the fittest means that certain organisms are more likely to survive with they traits in particular environments. This is because some organisms are more fit to live in a given environment whether it be due to temperature, weather, or predators.
One example is that dark moths are more fit for survival than light moths in many areas because they are able to camouflage against dark tree bark.
Hope this helps.