Amass movement called a/an occurs when sediment suddenly slips downhill in one large mass

According to the classic definition, a mass movement called a land side occurs when sediment suddenly slips downhill in one large mass

Even though that answer is approved, it is actually a Slump. The people that have approved that probably don't know what they are doing. I just took a final on this stuff and the answer is 100% Slump.

The answer i think is d

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