What is the objective function for the following shortest path problems? Select one: MIN 50 X_12 + 200 X_13 + 100 X_24 + 35 X_34 MIN - 50 X_12 -200 X_13 + 100 X_24 + 35 X_34 -X_12 - X_13 = 0 MAX -50 X_12 -200 X_13 + 100 X_24 + 35 X_34