: left her at least as well off  as before and possibly helped her.If the bundle x is revealed (directly or indirectly) as preferred to the bundle y and x ¹ y, then it is never the case that the y is revealed (directly or indirectly) as preferred to x; so the necessary and sufficient condition for well-behaved preference is (   )A:indirectly preferred B:convexity and monotonicity C:Strong Axiom of Revealed Preference D:Revovering indifference curve