Then A, C and E, now all answers except D. If you got that one right give yourself a big pat on the back, and maybe also have your head examined, because it's unhealthy to know that much about ancient timing rules.



Under Fourth Edition rules, there were instants and there were interrupts. Only interrupts could counter or modify a spell, and all interrupts had to be used before responding to the spell with any instants. So B wouldn't have been legal. But you'd get a chance to activate damage-prevention abilities in a separate later step, making C legal (since by then the Fireball would be black from the Deathlace).



The key difference between D and E is that Red Elemental Blast requires its target to be of the correct color when you cast it, while Pyroblast only checks the color on resolution. So you couldn't legally cast Red Elemental Blast targeting Fireball (making D illegal), but you could cast Pyroblast targeting Fireball, then interrupt Pyroblast with Sleight of Mind, changing Pyroblast to say "red", and then Pyroblast would counter the Fireball, making E a legal play. Although the timing rules are different now, E still works



B became legal when Magic switched from interrupts and "batches" of spells to the stack, as part of the 6th Edition overhaul; although many players still think so (and though it was true back in the early days), there's no requirement to let everything resolve once one spell has resolved. So Brainstorm can now resolve and draw you a Counterspell, and you can cast the Counterspell right away.