The Discovery of Norwegian Coins in North America Has Confirmed

The discovery of Norwegian coins in North America has confirmed which of the following theories?

A) Vikings discovered and settled for a time in North American during the eleventh century C.E.
B) Vikings had regular contact with Native Americans from North America.
C) The maritime journey from Scandinavia to North America was easier during the eleventh century C.E. due to a period of climatic warming.
D) Vikings should be credited with the European discovery of the Americas.