Final answer:
Sir Walter Raleigh encountered the Powhatan tribe upon his arrival in the Virginia, which was a large and powerful confederation controlling the Tidewater Virginia area.
A is correct
Step-by-step explanation:
The tribe that Sir Walter Raleigh encountered on his arrival in Virginia was the Powhatan. The Powhatan were a powerful confederation of many tribes united under the leadership of a chief known as the Wahunsonacock, who was also referred to as Powhatan.
This confederation was the largest in North American history and controlled the Tidewater Virginia area, extending from the Potomac River in the north to the Carolinas in the south and from the Chesapeake Bay inland to the west of what is now Richmond.