The purpose of Bitcoin exchanges is to ___. These exchanges are considered because they are (pp. 2-3) A. clear and settle payments in Bitcoins; highly safe; closely regulated B. clear and settle payments in Bitcoins; somewhat risky; unregulated C. allow conversions between Bitcoins and real-world currencies; highly safe; closely regulated D. allow conversions between Bitcoins and real-world currencies; somewhat risky; unregulated