A 'character encoding system' used in IBM mainframesAASCIIBISCIICBCDDEBCDICAnswer: D. EBCDIC Read Explanation: ISCII- Indian Standard Code for Information Interchange/Indian Script Code for Information Interchange BCD (Binary Coded Decimal) is a coding system for converting each digit in a decimal system into a binary number. A 'character encoding system' used in IBM mainframes - EBCDIC (Extended Binary Coded Decimal Interchange Code) Read more in App