This is another select a word challenge that has more than 1 correct answer. Of course probably the best answer is volis which can be deduced by the presence of hieraŭ in the sentence.
But. But I should point out that the endings of -u (present among the choices) and -us (not present among the choices) are also valid, since those endings are verb moods and tense with those moods is deduced by context or indicated by context.
So, mi volu manĝi fragojn hieraŭ is perfectly valid Esperanto, meaning something like I should have wanted to eat strawberries yesterday. And because the select a word challenges don't show what the sentence is being translated to, this does create a minor error if someone should decide to select volu and be marked wrong for it.