The correct Answer is A.
The Flow chart of the Carbon Cycle, will look as follows:
1. Carbon dioxide in the atmosphere.
2. Producers undergo photosynthesis (in this process plants among other producers like algae, use CO2 to produce energy).
3. Consumers eat producers (a primary level of consumer like a rabbit eats the producers or plants).
4. Decomposers return Carbon to the soil and release waste.
And the cycle continues again, by going back to step 1.
Nothing at all happens because pure water cannot conduct electricity
C) Sliver Carbonate AgCO3
Reactant C is the limiting reactant in this scenario.
Explanation:
The reactant in the balanced chemical reaction which gives the smaller amount or moles of product is the limiting reagent.
Balanced chemical reaction is:
A + 2B + 3C → 2D + E
number of moles
A = 0.50 mole
B = 0.60 moles
C = 0.90 moles
Taking A as the reactant
1 mole of A reacted to form 2 moles of D
0.50 moles of A will produce
= 
thus 0.50 moles of A will produce 1 mole of D
Taking B as the reactant
2 moles of B reacted to form 2 moles of D
0.60 moles of B reacted to form x moles of D
= 
x = 2 moles of D is produced.
Taking C as the reactant:
3 moles of C reacted to form 2 moles of D
O.9 moles of C reacted to form x moles of D
= 
= 0.60 moles of D is formed.
Thus C is the limiting reagent in the given reaction as it produces smallest mass of product.