The two rappers Akon and B-Kon are recording a song together and are negotiating how to split the royalties from the song (1 million in total). The negotiations work in the following way: First Akon proposes one of three options: (i) an equal split, (ii) Akon gets 75% and B-Kon gets 25%, (iii) Akon gets 25% and B-Kon 75%. Then B-Kon can either accept or refuse; if he refuses the record is not released and nobody gets anything. Both rappers are planning to retire after this song.

(a) Draw the game tree. B-Kon announces that he will refuse any offer that is worse than 50%. Is this credible? Explain why (not)?

(b) Change one of B-Kon's possible payoffs in the game tree such that B-Kon's announcement becomes credible.

(c) How could B-Kon achieve a change such as in (b)? What could be the disadvantages?