In this task, You are given an open-domain question that can be answered based on factual information. Your task is to provide \*short\* answer (in a few words only) for the given question. The short answer can be one or more entities or it can also be boolean \*yes\* or \*no\*.
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Question: where does the surname janse van rensburg come from

Answer: South African


Question: when did thanksgiving start as a national holiday

Answer: 1789


Question: what caused the american oil crisis of 1974

Answer:
an oil embargo