Had to look for the options and here is my answer.
When we say that a redox reaction is spontaneous, this would mean that there is a formation of positive voltage <span>across the electrodes of a voltaic cell. Therefore, the system that this kind of reaction produces electrical energy is in a GALVANIC CELL. Hope this helps.</span>
Answer:
The third one makes the most sense
Then we would not have oxygen because plants give oxygen in order to breathe
Carbon has 4 valence electrons so to gain a noble gas electron configuration, which has 8 valence electrons and is the most electrically stable, carbon needs 4 more electrons.
