Which of the following animals occupies more than one trophic level in the same ecosystem at the same time?

Given below are two statements:
Statement $I$: In an ecosystem,there is a unidirectional flow of energy from the sun through producers to consumers.
Statement $II$: Ecosystems are exempted from the $2^{nd}$ law of thermodynamics.
In the light of the above statements,choose the most appropriate answer from the options given below:

How many statements are correct?
$(a)$ Some animals like cockroaches,crows,etc.,are omnivores.
$(b)$ Detritus food chain $(DFC)$ begins with dead organic matter.
$(c)$ Each trophic level has a certain mass of living material at a particular time called as standing crop.
$(d)$ Species composition and stratification are two main structural features of an ecosystem.

Which one of the following animals may occupy more than one trophic levels in the same ecosystem at the same time?

What is the correct sequence in a hydrosere (hydrarch succession)?

Ecological succession is a