The answer in this question which is asking about the link between the CAC and oxygen is that the major product of the cac is nadh, the principle electron donor to the o2 , the last electron acceptor in the electron-transport system. The answer in this question is D.
The net force is the vector sum of the two forces, since they’re acting in opposite directions one is negative (left) so
-5 + 7 = 2 to the right
Magnitude is 2
Direction is right
