If anyone could explain which block in the periodic table has metals with changing oxidation numbers and why, it would be greatly appreciated

D-block

Explanation:

Transition metals are metals of the d-block elements located between group 2 and 3 in the periodic table. They are called d-block element because the filling of electrons in their electronic configuration ends in the d-orbital.

Now, they have variable oxidation state because of their partially filled 3d orbital i.e the 3d orbital is not completely filled.

i think a, hope it .

explanation:

i think it's c. i'm not sure but i think so.