..........

With only a list of attribute names to go on only guesswork and assumptions are possible. This looks like homework. Were you given a list of FDs or are you expected to guess?

Your Exhibition Theme table implies ExhibitionTheme -> Exhibition. If that's accurate then why do those attributes also appear in the Exhibition table, implying a non-key dependency?

Isn't it also possible that a work of art appears in more than one exhibition?