Need Help: How does the GK Purifier cleansing flame actually work?

[Wildcard]

So, as the title suggests:

When in melee, after you have passed psychic test for cleansing flame, do you:

a) Roll a single d6, and on a 4+ every enemy model takes a wound

or

b) Roll as many d6's as there are enemy models in the combat, and of those that get 4+ will take a wound?

The way we read it at first (and have so far played), the right answer was option 'b'. However, there was this one guy on our local gaming store that said it was the option 'a', and this left us wondering..

So, which one is right option? (None of our group speaks / reads english natively, so naturally this led into some fiery discussion :) )

Thanks again in advance!

[AbusePuppy]

The latter is the correct interpretation; one die is rolled for each enemy model in the combat, wounding on a 4+. Successful wounds are then allocated just as they normally be (and independent characters are not separate for these purposes.)