The s-block elements are the elements in Group 1 and Group 2 of the periodic table, plus hydrogen and helium. They are called "s-block" elements because their valence (outermost) electrons are in the s subshell of their atoms.
Aluminium is not an s-block element. It is located in Group 13, which is part of the p-block elements. Its valence electrons are in the p subshell of its atoms.
Therefore, the answer is aluminium.