0.36 M Al3+ ions and 0.12 M Cl- ions
0.12 M Al3+ ions and 0.040 M Cl- ions
0.12 M Al3+ ions and 0.36 M Cl- ions
0.040 M Al3+ ions and 0.040 M Cl- ions
none of these
It is the third choice.
Since AlCl3 is made of 1 aluminum ion and 3 chloride ions, the concentration of the chloride ions is 3X the concentration of the aluminum ion.
Therefore, the third choice is the only choice that fits this condition.