First, notice that there's a drop in concentration after glyceraldehdye 3-phosphate to 1,3-bisphosphoglycerate. Thus, the conversion is impaired here.
Next, it's somehow remembering which freaking enzyme is involved. Which is glyceraldehyde-3-phosphate dehydrogenase in the glycolytic pathway. This is one where if you know the substrate name you know the enzyme name.