Final answer:
The melting point of the metal determines whether it can be cut with a cutting torch.
Step-by-step explanation:
The single factor that determines whether you can cut a particular metal with a cutting torch is its melting point. Metals with lower melting points can be easily cut with a cutting torch because the torch generates very high temperatures that can melt the metal and cut through it. On the other hand, metals with higher melting points may require specialized cutting techniques or tools.