The answer choices for each dropdown are the numbers -2 to 5.

For the electrons 'owned' does that refer to the charge on each carbon or something. Would the top carbon for GAP be zero because there is no space for free electrons on it?

Glyceraldehyde 3-phosphate dehydrogenase catalyzes a coupled reaction that results in the oxidation of GAP and formation of the high phosphoryl-transfer potential product 1,3-BPG (See A5 resource). Identify the site of oxidation in GAP by counting the electrons "owned" by each of its carbon centers and comparing them to electrons "owned" by each carbon center in 1,3-BPG (See B3 resource). GAP 1,3-BPG