Who were the earliest people to arrive in the british isles

The British Isles have experienced a long history of migration from Europe. The ancient migrations have come via two routes: along the Atlantic coast and from Germany–Scandinavia. The first settlements came in the Palaeolithic and Mesolithic periods. The earliest evidence of human presence in Ireland is dated to 10,500 BC.[1][2][3]

Research into this prehistoric settlement is controversial, with differences of opinion in many academic disciplines. There have been disputes over the sizes of the migrations and whether they were peaceful. In the latter part of the second millennium, the finds of archaeology allowed a view of the settlement pattern to be inferred from changes in artefacts. Since the 1990s the use of DNA has allowed this view to be refined.

c is the correct answer for this question.