Ferguson is right, 2 Champions Leagues with United, 1 ECWC with United and 1 ECWC with Aberdeen.
Paisley is right, 3 European Cups with Liverpool and 1 UEFA Cup with Liverpool.
Trappattoni is right, 1 European Cup with Juventus, 1 ECWC with Juventus, 2 UEFA Cups with Juventus and 1 UEFA cup with Inter.
Ancelotti is incorrect, as a manager he's only won 3 European trophies (as a player he's won European trophies too, but the question was regarding managers). He won 2 Champion's Leagues with AC Milan, and 1 Champion's League with Real Madrid, but that's it. Yes, if you include the Intertoto Cup, and the Super Cup, he's won another 4, but they don't count.
There's 1 more to get, and he's by some distance the most obscure answer!