The Nitrogen Found in Carnivores Would Follow Which of the Following

The nitrogen found in carnivores would follow which of the following paths?

A) plant $\rightarrow$ air $\rightarrow$ carnivore
B) herbivore $\rightarrow$ plant $\rightarrow$ air $\rightarrow$ carnivore
C) air $\rightarrow$ bacteria $\rightarrow$ plant $\rightarrow$ herbivore $\rightarrow$ carnivore
D) air $\rightarrow$ plant $\rightarrow$ bacteria $\rightarrow$ herbivore $\rightarrow$ carnivore