Which of the following can upset the balance of an ecosystem? too much water
not enough water
too much light
not enough light
all of the above
none of the above

All of the above.

Explanation:

all four of those situations can cause plants to die and animals with it. Without plants, herbivores will not have food and either die or leave, and without herbivores, carnivores will face the same situation.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it