Australia, the UK, and Ireland do not count because they only have one coastline. For instance, Australia may touch both the Pacific and the Atlantic oceans, but it only has one coastline all the way around the country.
This quiz is less straightforward than it sounds because there are marine lagoons, such as one on Saint Martin, that give a county more than one coastline if the lagoon is counted as part of the sea. Saint Martin is why I couldn’t include territories in this quiz.