How do you group the following languages into pairs which are closely related from a historical point of view: Romanian, Czech, Dutch, French, Gaelic, German, Russian, Welsh?
ARomanian and French; Czech and Russian, Dutch and German, Gaelic and Welsh
BGerman and French; Romanian and Dutch; Czech and Gaelic; Russian and Welsh
CRussian and German; Welsh and French; Romanian and Gaelic; Czech and Dutch
DCzech and Russian; German and Romanian; Welsh and French; Gaelic and Dutch