Concept:A word can be formed only if every letter in it is present in the given word.Explanation:Given word: SHORTING.Available letters: S,H,O,R,T,I,N,G.THORN uses T,H,O,R,N, all present.NITRO uses N,I,T,R,O, all present.NOISE uses N,O,I,S,E; there is no E in SHORTING.STING uses S,T,I,N,G, all present.So, NOISE cannot be formed.Answer:Option C: NOISE