Balance H2SO4+KOH->K2SO4+HOH

Shown in the pic.

Explanation:

Tips:

Treat the SO4^2- group as 1 unit so balance the SO4^-2 on both sides, since they do not become chemically altered (don't split it into S's and O's).

Balance element by element, dealing with the groups that don't change first (in this case, the SO4^2- groups), then progress to the molecules with fewer and fewer atoms, dealing last with elements/atoms.

- aluminum and copper chloride.

- the chloride ion to separate the aluminum from the oxygen so that the aluminum can react with the copper ions (and the water molecules).

c is the answer because when something is left after something evaporates that shows the chemical change.