Question

In which natural cycle must an important gas in Earth's atmosphere be fixed before plants can use it?

A. sulfur cycle
B. carbon cycle
C. nitrogen cycle
D. oxygen cycle

Answer 1

Answer:

C. Nitrogen Cycle

Hope it helps

Answer 2

Step-by-step explanation:

Stage 1: Nitrogen Fixation

To be used by plants, the N2 must be transformed through a process called nitrogen fixation. Fixation converts nitrogen in the atmosphere into forms that plants can absorb through their root systems.