Final answer:
Iron oxide (FeO) contains a transition metal, specifically iron.
Step-by-step explanation:
The compound that contains a transition metal is option D, iron oxide (FeO). Iron is a transition metal, and in this compound, it has an oxidation state of +2. Transition metals are elements found in the d-block of the periodic table and often exhibit multiple oxidation states. They have partially filled d orbitals which allow them to form compounds with a variety of charges.
The correct answer is D. iron oxide (FeO), as iron (Fe) is a transition metal. Transition metals are elements found in the d-block of the periodic table, known for their ability to exhibit more than one oxidation state, which is the case for iron in different compounds.