$\begin{array}{1 1} \text{(a)(i) It does not form oxoacid (ii) Hydrogen fluoride is a solid} \\ \text{(b)(i) It forms multiple oxoacid (ii) Hydrogen fluoride is a Solid} \\ \text{(c) (i) It forms only one oxoacid (ii) Hydrogen fluoride is a liquid} \\ \text{(d) (i) It is the most electropositive halogen (ii) Hydrogen fluoride is a liquid}\end{array} $
