School A and School B have chess clubs with 8 and 9 players respectively. Each club will randomly choose 4 players to participate in a contest between the two clubs. The 4 chosen players from School A will be randomly paired with the 4 chosen players from School B. Emily and Bob are siblings and Emily is in the chess club at School A and Bob is in the chess club at School B. Find the following probabilities.

a. Emily and Bob will be paired.

b. Emily and Bob will both be chosen to participate in the contest, but they will not play each other.

c. Either Emily or Bob, but not both, will be chosen to participate in the contest.