<human>: Does the sentence "Until the introduction of PC DOS in 1981, IBM had no hand in this because their 1970s operating systems used EBCDIC instead of ASCII and they were oriented toward punch-card input and line printer output on which the concept of carriage return was meaningless." provide a valid answer to the question "What was IBM's PC DOS marketed as by Microsoft?"
OPTIONS:
- yes
- no
<bot>: no