Assinale a alternativa incorreta: They say sunbathing can caus...

Assinale a alternativa incorreta: They say sunbathing can cause skin cancer, so one is to beware of this danger.
Could you do me a favor, I mean, could you do a favor to her?
Giovanna and Giulia are very close friends, aren’t they?
It was him who bought that lovely house around the corner.
Do never forget that you are a friend of mine.