The *independent* variable is the one that you always can control. However, the dependent variables are not since they **depend** on another.
I think its c because solid,liquid nor plasma really fits to the description and i don't really know the last one so the best option is probably C.
Answer:
equal the number of electrons.
Explanation:
The answer is D
FeCl3 + 3 NH4OH → Fe(OH)3 + 3 NH4Cl