Answer:
The correct answer is: 6 molecules of carbon dioxide are required in order to produce 1 molecule of glucose.
Glucose is synthesized in light-independent phase of the photosynthesis by cyclic process called Calvin cycle.
It takes place in the chloroplast and utilize ATP and NADPH produced in light-dependent phase of the photosynthesis.
Calvin cycle is divided into three parts: carbon fixation, reduction, and regeneration.
The cycle fixes 1 molecule of carbon per rotation. In addition, it requires 3 ATP and 2 NADPH in a single turn.
The cycle turns 6 times to produce one molecule of glucose. Hence, it requires 6 CO₂, 18 ATP, and 12 NADPH to fix one molecule of glucose.
