The explanation for the correct answer for this question says: We discuss the importance of aligning the standard of care clauses in your agreements in our video Negotiating the C401 Agreement (7:38). As far as I can tell there is no discussion of that topic in the video. There is a general discussion about aligning the agreements, but none with respect to the standard of care. (Also, please note that the sample C401 document in the video is mislabled as the Standard Form of Agreement Between Architect and Contractor. It should be the Standard Form of Agreement Between Architect and Consultant.)
Update: I found the reference for the standard of care explanation. It is in Objective 1.4 in the video called ‘Understanding the Standard of Care’. Not in Objective 3.2 ‘Negotiating the C401 Agreement video’.