Rule reminder
Dislocation (dislocazione) requires a resumptive clitic: 'Il libro, lo ho letto.' Topicalization (topicalizzazione) fronts an element WITHOUT a resumptive clitic and is associated with formal or literary Italian: 'Questo libro ho letto, non quell'altro.' Topicalization is used for contrast or focus in careful written Italian, whereas dislocation is colloquial.
Which sentence uses topicalization (no resumptive clitic) rather than left dislocation?