A property generates $7,000,000/year in revenue. It incurs $2,000,000/year in operating expenses and $1,000,000/year in non-operating expenses, producing a net operating income of $5,000,000 and a net income of $4,000,000. If the property sold for $100,000,000, what was the cap rate used in the transaction?

a) 4.0%

b) 4.5%

c) 5.0%

d) None of the above