Although CBA is not so homophone, the term arsed in certain areas is defined as being slightly vulgar, and that is why the phrase is rather unsuitable in a formal context. It may be rude or haughty especially when it touches on what someone is asking. Among peers it is generally accepted as casually spoken slang that means low motivation. But applying it to colleagues, teachers or adults, it may appear disrespectful. Reserving the term CBA to informal situations would be the best when everyone is used to casual language, and the use of slang phrases. Know more about
cba meaning