Regarding assertion and reason, choose the right option.
Assertion [A]: Food webs are formed because of complex feeding relationships between organisms.
Reason [R]: Most organisms feed at one or more trophic levels in a food chain.
Many living organisms are omnivores. It is difficult to place these organisms in a linear food chain. For example, when a bear eats berries, the bear is functioning as a primary consumer but when the same bear eats a plant-eating rodent, the bear is functioning as a secondary consumer. So, the diet of some organisms makes the relationships complex and a food web is formed.