Answer:
I think the answer is C
''Reusing plastic bags''
Explanation:
Removing carnivores from a forest has a great impact on a environment since the population of the herbivores will increases drastically and the dynamic equilibrium of the area will be greatly effected.
If we look at choice B '' Heating homes with fossil fuels'', this will also have a big impact on the earth since fossil fuels are non-renewable and take centuries to form. Heating homes with them will result in loss of fossil fuels.
Now let's look at choice D ''Adding heavy metals to the water supply''. Heavy metals are dangerous to the human health and even cause cancer. This will cause thousands of deaths and will also have a great impact on the global stability.
This leaves choice C ''Reusing plastic bags''. This will cause less pollution and less harm to wildlife but doesn't have any big threat to the global stability. As in changing the world population or causing deaths in large numbers.
so I think choice C is the answer
A cell. it is the smallest unit of life that can reproduce indepentantly
To enable primary cells to be prepared for excised tissues
It is very True to make the function of the cell work well