Question: How many countries comprise the region that includes a country where North Sea oil was discovered in the 1970s?
Sentence (from "List of oil and gas fields of the North Sea"): In terms of the oil industry, "North Sea oil" often refers to a larger geographical set, including areas such as the Norwegian Sea and the UK "Atlantic Margin" (west of Shetland) which are not, strictly speaking, part of the North Sea.
Relevant evidence: No