d. they are not found in the first two principal energy levels
The other choices are all correct statements about d orbitals.
D orbitals are associated with transition elements, which are elements in the periodic table that have partially filled d orbitals in their outermost energy level. These elements are typically found in the middle of the periodic table. Therefore, choice a isn’t the correct answer.
There are five types of d orbitals: dz2, dxz, dyz, dx2-y2, and dxy. These orbitals have different shapes and are oriented differently in space. Therefore, choice b isn’t the correct answer.
D orbitals are filled before p orbitals in the same principal energy level. In the periodic table, elements with d orbitals are typically found before elements with p orbitals. Therefore, choice c isn’t the correct answer.
D orbitals are not found in the first two principal energy levels. They are found in the third principal energy level and higher. Because choice d comprises an inaccurate statement about d orbitals, that is the correct answer.