D And F Block Elements

In chemistry, an amphoteric species is a molecule or ion which can react as an acid as well as a base. This word is derived from the Greek word amphotericin which is meant for "both": Many metals like zinc, tin, lead, aluminium, beryllium, etc formamphoteric oxides or hydroxides. Here both and can show the property of acidic as well as basic oxide both. Thus option is correct.

Transition metals exhibit variable valency

Cerium is the most useful members of lanthanide series.