Which of the following enzyme is used to fix CO2 through Calvin cycle?

• A. Ribose -1, 5- bisphosphate carboxylase
• B. Ribulose -1, 6- bisphosphate carboxylase
• C. Ribose -1, 6- bisphosphate carboxylase
• D. Ribulose -1, 5- bisphosphate carboxylase