The correct answer is b) 2 ATP.
Glycolysis is the process through which glucose is transformed into pyruvate, generating energy in the form of ATP. During glycolysis, a total of 4 ATP molecules are produced through substrate-level phosphorylation. However, 2 ATP molecules are consumed in the initial steps of the glycolysis pathway. Therefore, the net gain of ATP from glycolysis is:
Total ATP produced: 4
ATP consumed: 2
Net gain: 4 – 2 = 2 ATP
This net yield of 2 ATP is crucial for cellular metabolism, as it provides the necessary energy for various cellular processes.