I think the key here is lines 49-53. It basically states that it doesn't mean that something is lost forever or no longer a "tradition" on the basis that the people were prevented, by circumstances beyond their control from exercising a tradition for a given period of time. If you know this, you should be less tempted by (A) or (E) since both don't really seem to have been prevented by circumstances beyond ones control (at least we aren't given much evidence) whereas (C) clearly can be considered "traditional" since the discontinuation resulted from circumstances beyond one's control. Hope this helps!
E is also certainly wrong because you wouldn't need the 1991 ruling to decide on it. The earlier ruling could also set the precedent. Few elder Alaskan Natives practicing the craft means that it has been produced "within living memory." 1991 is useful because it overturns and redefines the ruling of 1986.
The pattern to look for here is a handicraft has been prevented from being produced due to colonization.
Another reason A is wrong is because handicrafts practiced several millenia ago don't fall under being traditional; they were lost "forever" ago and were exercised too far in history that the practice doesn't qualify as traditional.
B is out of scope; just because the species is endangered doesn't mean that the handicraft involved is traditional.
D is wrong because only a few people knew about it; doesn't really sound "traditional:.