Answer: Alice has the prize
Explanation:

Line 1:
Alice: Bob doesn’t have the prize (T) ... either Alice or Carol
Bob: I don’t have the prize (T) ... either Alice or Carol
Carol: I have the prize (F) ... either Alice or Bob
Alice is true for all of them!
Line 2:
Alice: Bob doesn’t have the prize (T) ... either Alice or Carol
Bob: I don’t have the prize (F) ... Bob
Carol: I have the prize (F) ... either Alice or Bob
nobody satisfies all three statements.
Line 3:
Alice: Bob doesn’t have the prize (T) ... either Alice or Carol
Bob: I don’t have the prize (F) ... Bob
Carol: I have the prize (T) ... Carol
nobody satisfies all three statements.
Line 4:
Alice: Bob doesn’t have the prize (F) ... Bob
Bob: I don’t have the prize (T) ... either Alice or Carol
Carol: I have the prize (T) ... Carol
nobody satisfies all three statements.
Line 5:
Alice: Bob doesn’t have the prize (F) ... Bob
Bob: I don’t have the prize (F) ... Bob
Carol: I have the prize (T) ... Carol
nobody satisfies all three statements.
Line 6:
Alice: Bob doesn’t have the prize (F) ... Bob
Bob: I don’t have the prize (T) ... either Alice or Carol
Carol: I have the prize (F) ... either Alice or Bob
nobody satisfies all three statements.