The duty of care requires advice that serves the client's best interest, which presupposes that the adviser reasonably understands what the client is trying to achieve. With a retail client that means asking, and keeping current, about finances, sophistication, experience and goals (the investment profile); with an institutional client it means understanding the mandate. The adviser must then reasonably believe the advice fits those objectives, which requires a reasonable investigation into the investment itself so that advice does not rest on materially inaccurate or incomplete information. Cost is one of many factors; a higher-cost product may be recommended where the adviser reasonably concludes other features serve the client's interest. Account type recommendations, rollovers and the choice between advisory and brokerage are expressly within the duty.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.