What is the key element found on co2 and glucose

Carbon

CO2 = carbon dioxide
C6H12O6 = glucose

The correct answer is: making up measurement to record

This is what i found on google “phytoplankton, tiny organisms that live in the ocean, are autotrophs. some types of bacteria are autotrophs. most autotrophs use a process called photosynthesis to make their food.” i hope this you for what your looking for