Hey everyone
To me A and B are correct, but here is CFAI explanation below:
So i get it, B is correct because an analyst’s opinion is not adequate basis for action in changing a recommandation. A is incorrect, i don’t understand their explanation, so if he had heard the opinion, and it sparked him to conduct additional research and investigation, then it is OK to change the recommandation, however, changing it without conducting any additional research is also OK… Since answer A is incorrect.