The correct answer is option B, that is, hypothesis.
A hypothesis refers to an anticipated illustration for an occurrence. It refers to a proposed illustration or a supposition made on the groundwork of inadequate proof as an initiation point for further investigation. In order for a hypothesis to be a scientific hypothesis, the scientific method needs that one can examine it.
Answer:
Examples of Chemical Changes
Burning wood.
Souring milk.
Mixing acid and base.
Digesting food.
Cooking an egg.
Heating sugar to form caramel.
Baking a cake.
Rusting of iron.
Solution :
Molar mass of 
is :
M = 6×12 + 6×1 g
M = 78 g
78 gram of contains 
molecules.
So, 89.5 gram of contains :
Now, from the formula we can see that one molecule of contains 2 hydrogen atom . So, number of hydrogen atom are :
Hence, this is the required solution.
I would say C is the most correct.
In D it depends on what water source you're using. Let's say it is a waterfall, then the source of the water (melting ice or a lake) may disappear in the future.
If you're using underwater "windmills" placed in the ocean, then you would expect it to last a while as the ocean will not disappear in the near future.
