Answer:
Step-by-step explanation:
A chemical change.
Usually those are irreversible. Or they may be reversible, but the form they take may leave your object not the same as they started out.
A physical change might be just as deadly. If the object melted like a chocolate Easter Bunny then the object would be irreversible as well. Take a better example.
Suppose you are talking about a Gold Coin. If you heated it so it melted, the gold would retain its value, but the fact that it is a coin and valuable as such, means that it has lost that part of its value.
I really don't know. My instincts tell me that the chemical change is more dangerous, but I can't rule out the other choice..