The answer is C i loooked it up
In a typical ECG (Electrocardiogram) the first wave obtained is P wave; The P wave represents the depolarization of the atria. After this, the QRS complex is formed. The QRS wave represents the depolarization of the ventricles. During the depolarization phase, the ventricles contracts and pushes the blood into the atria. Hence, the correct answer is depolarization of the ventricles.
There are more than 5 factors, but here are perhaps the most important ones:
1) Light: Light energy is a crucial component in photosynthesis, as it is the primary energy source of the process.
2) Carbon Dioxide: Another key ingredient in photosynthesis.
3) Temperature: There is an optimum temperature for photosynthesis that varies from organism to organism. Too cold or two hot, and rate of photosynthesis will be lower.
4) Water - Like almost all life process, water is a key component in photosynthesis.
5) Oxygen. A common misconception is that plants only "breathe in" carbon dioxide and expel oxygen. Plant cells actually require oxygen as well in order to function, and thus oxygen is a necessary part of photosynthesis.