@GrammarTable Few sentences live in a vacuum. These sentences would be part of a ' conversation' - either written or spoken. This is where application of pragmatics can assist the confused pedant.
@GrammarTable I cannot view one as 'correct' and the other 'incorrect'. I view them as preferences and regional, Continental, cultural, etc. differences.
The point I like to consider is: Is there confusion caused by the words chosen?
@GrammarTable From the opening lines of their mission statement: (They do not capitalize the word in question.)
"Founded in 1956, the Council of Independent Colleges (CIC) is an association of nonprofit independent colleges and ..."
https://t.co/bCwTyVSBxz
@GrammarTable Whichever way is considered 'proper' I would use 'Who', since 'Whom' has been steadily dropping from daily speech. I would have no problem if 'That' were used. I have regularly heard the 'That'/'Who' exchange in regular speech.