The stability of +1 oxidation state increases in the sequence:

• A

  $\mathrm{Tl}<\mathrm{In}\ne \mathrm{Ga}<\mathrm{Al}$

• B

  $\mathrm{In}<\mathrm{Tl}<\mathrm{Ga}<\mathrm{Al}$

• C

  $\mathrm{Ga}<\mathrm{In}<\mathrm{Al}<\mathrm{Tl}$

• D

  $\mathrm{Al}<\mathrm{Ga}<\mathrm{In}<\mathrm{Tl}$