Elements of group-15 form compounds in +5 oxidation state. However, bismuth forms only one well characterisedcompound in +5 oxidation state. The compound is
Bismuth commonly shows +3 oxidation state instead of +5 oxidation state due to inert pair effect (recultance of s electrons to take part in bond formation)
But fluorine has small size and high electronegativity than oxygen, chlorine and sulphur.
Therefore bismuth forms BiF5 and show +5 oxidation state.
Hence the correct option (ii).