The nitrogen cycle is an example of a(n) biogeochemical
cycle. Its processes include the conversion of atmospheric nitrogen into ammonia, which is called
Choose... photosynthesis, denitrification, nitrogen limitation, nitrogen fixation
. Nitrogen is returned to the atmosphere in the process of
Choose... denitrification, nitrogen fixation, nutrient return, nitrogen limitation

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.

Your answer will be b action plan.

Iam a beginner but i sa answer is