PLEASE HELP!! Which variable is most important to the following problem?

Jackie played the first 8 minutes of a basketball game. Layla then replaced
her for the rest of the half. Layla started the second half and was replaced by
Jackie with 9 minutes left in the game. If each half is 16 minutes long, how
long did Jackie play?

A. The number of players who played during the game

B. The number of minutes Layla played in the second half

C. The total number of minutes Jackie played

D. The length of the half