Sentence:  Chewing it over with his colleagues and in his own mind , he reaches a tentative identification of the question - tentative because it may <WSD>change</WSD> as he explores it further and because , if no tolerable answer can be found , it may have to be changed into one which can be answered . 
Meaning of the word marked with <WSD> tags:  undergo a change; become different in essence; losing one's or its original nature