You are running an arm-wrestling competition with four contestants. When two contestants are matched, the strongest one always wins, and there are no ties. Using Merge Sort, how many matches are needed to sort the competitors from weakest to strongest? (Select ONE answer)
A. 4 matches
B. 5 matches
C. 6 matches
D. 4 or 5 matches, depending on the outcome of certain matches

D. 4 or 5 matches