In which sentence below is the comma used correctly?

a. in the first round of the tournament, i played one of the best teams.
b. in the first round, of the tournament i played one of the best teams.
c. fortunately i had, a spare set of keys with me.
In which sentence below is the comma used correctly?
Answer:


the right answer is a. in the first round of the tournament, i played one of the best teams.