Aldo sugar that is intermediate between respiration and photosynthesis:

Explanation

The correct answer is glyceraldehyde-3-phosphate (G3P), which is an aldose sugar that functions as an intermediate in both glycolysis and the Calvin cycle of photosynthesis. During glycolysis, G3P is generated from glucose and further metabolized to pyruvate. In photosynthesis, G3P is formed during the Calvin cycle when carbon dioxide is fixed. Other options like glucose, dihydroxyacetone, and fructose either do not have the necessary aldehyde group or do not function as intermediates between these two processes.