I created the two tables and entered data in them exactly as stated in the question and ran statements A and B. Both returned the exact same result as below. The only difference was the heading for the third column, one said UniqueID, the other Unique_ID.

FRED 1 3

FRED 2 3

FRED 3 3

FRED 4 3

BILL 1 2

BILL 2 2

BILL 3 2

BILL 4 2

RON 1 1

RON 2 1

RON 3 1

RON 4 1