Which type of photosynthesis where carbon dioxide is fixed and reduced twice?

The type of photosynthesis where carbon dioxide is fixed and reduced twice is known as C4 photosynthesis. In this process, carbon dioxide is initially fixed into a four-carbon compound, which is then converted into a three-carbon compound for the Calvin cycle. This mechanism allows plants to efficiently capture carbon dioxide and thrive in high light and temperature environments. Examples of C4 plants include maize and sugarcane.