Why do experts use one kind of explosive for steel columns and another for concrete columns

I think it’s the first option.

The second option isn’t true because the fabric protects people from the debris, it doesn’t actually explode the concrete

The third option isn’t true because steel and concrete need different explosives, not necessarily “more” If anything I think concrete needs more explosives because steel needs to be broken in one place

The last option could be true but I didn’t read anything about putting steel explosives in holes

The answer is number 4.