Answer:
In C3 photosynthesis, the reactions that require ATP take place in
B) the Calvin cycle alone.
Explanation:
In C3 PLANTS PHOTOSYNTHESIS OCCUR IN TWO STEPS-
1. LIGHT stage , WHICH TAKES PLACE IN LIGHT. In this stage water is split and ATP is released.
2. DARK stage, which takes place in dark. This the stage where calvin cycle takes place which require ATP, i.e energy. In this process sugar is produced with help of carbon dioxide. In this carbon dioxide is accepted by 5- carbon molecule ribulose-1, 5-biphosphate, which result into two molecules of 3- phosphoglycerate. this three carbon compound. hence is called as C3 pathway. hence C3 plants.