In the steps of the Born-Haber cycle for Na₂O, how many ionization energies (IE) and how many electron affinities (EA) are there?

• A. 1 IE, 1 EA
• B. 2 IE, 2 EA
• C. 2 IE, 1 EA
• D. 1 IE, 2 EA
• E. 2 IE, 0 EA

Answer: (D)