The correct answer is option A, Plants take in carbon dioxide and produce glucose-animals consume plants-animals break down glucose and release carbon dioxide.
Reason -
The carbon cycle comprises of following stages
a) Release of carbon dioxide in the atmosphere – carbon is released in the form of CO2 as a result of exhalation process during respiration of all living species or by burning of fuels or decomposition of dead organic matter etc.
b) Carbon uptake by plants – Plants take in CO2 to produce glucose and oxygen during the process of photosynthesis.
c) Usage of carbon product produced by plants – All animals or human beings consume the plant to take in the carbon entrapped by the plant in the form of glucose
d) Release of carbon by animals/living species – Again after consuming plants, the living beings including animals exhale out CO2 by respiration, or microorganisms feed on the dead remains to release carbon in the soil
This process continues in a cyclical chain manner again and again.