Why were the english unsuccessful in the launching an attack against thd vikints

The answer is C. They could not agree on how to best defend the region.

For 250 years, the Vikings were protagonists of the history of England: first as looters of cities, later as warlords who litigated with the Saxon royal house for the dominion of the island and finally as kings of the English. In the year 793, the Vikings landed at Lindisfarne, sacked the monastery and killed all the monks. To avoid the constant Viking attacks on their lands, the kings of the English had to pay large sums of money. During the ninth century, the Vikings imposed on the Saxon kings a heavy tribute, the danegeld, with which they bought peace to the Vikings.