Standard electrode potential values of  ${\mathrm{Al}}^{+3}/\mathrm{Al} \mathrm{and} {\mathrm{Tl}}^{+3}/\mathrm{Tl}$are respectively -1.66 V and +1.26 V.The correct statement is 

${\mathrm{Tl}}^{+3}$is a strong reducing agent. 

Al is more electropositive than Tl

Al is more stable in aqueous medium

Tl is more electro positive than Al