Having a really hard time following this diagram of the Kreb cycle and I need to answer these questions:

Question

1. Total number of NADH molecules produced for each glucose molecule in the Krebs cycle.
A)2 B)4 C)6 D)8 E)10

2. The theoretical yield of ATP from each NADH molecule.
A)1 B)2 C)3 D)4 E)5

3. Total number of CO2 molecules produced in the Krebs cycle for each pyruvate molecule.
A)1 B)2 C)3 D)4 E)5