Answer:
Option A. X represents water and Z represents oxygen.
Step-by-step explanation:
Glucose + Z → X + Y + Energy
The equation above gives an illustration of the Combustion of glucose to produce energy needed for metabolic activities.
Thus, writing a balanced equation will help us to identify what X and Z most likely represent. This is illustrated below :
C6H12O6 + 6O2 —> 6H2O + 6CO2 + Energy
We can see clearly that Z is constant i.e Z is oxygen. But X could be either CO2 or H2O.
Considering the options given above, only option A states that Z is oxygen. Therefore, X must be water (H2O).