Find out in which step each auxotroph has a mutaion

You are studying a biochemical pathway in the bread mold NEUROSPORA crassa that is involved in the production of the compound C. You know that compounds A,B,D,E,F are required in this pathway, but you do not know the order in which they are synthesized. In order to study this, you isolate five auxotrophic strains that cannot synthesize compound C. Each of these strains has a single mutation affecting a single step of the pathway. From the following table infer the biochemical pathway and determine in which step each auxotroph has a mutaion. (“+” represents growth of the auxotroph on minimal meduim supplemented with the compund. (“-” represents no growth of the auxotroph on minimal meduim supplemented with the compound)

Mutants A B C D E F
1 – – + – + –
2 – + + + + +
3 – + + – + –
4 – – + – – –
5 – + + – + +