Multiple choice ______ will be the first stable product when CO2 is added to phosphoenol pyruvic acid. Phosphoglycolate Pyruvate Glyceraldehyde-3-phosphate Oxaloacetate Phosphoglycerate Reveal answer Fill a bubble to check yourself D Correct answer Explanation Oxaloacetate will be the first stable product. Oxaloacetate will be the first stable product.