Sorry but this one is a really bad exercise.

Firstly, it doesn't accept 'Peter', and demands 'Péter'. That is definitely overly picky, particularly when other exercises ask for 'Susan' as a translation of Zsuzsa or 'Leslie' for Laszló.

Secondly, it is quite an unnatural sentence in English anyway. "Peter sees tall girls, not short ones". I'd say it's unusual to refer to people like that - the natural thing is to repeat 'girls'. But "Peter sees tall girls, not short girls" is not accepted.

This business of requiring Péter in English has got to be fixed!