I need help with this problem, both parts.

ECON 402 HW 4 Page 2 4 SPNE (20 points) For the following games, find the SPNE and one PSNE that is not subgame perfect. Explain why the PSNE you find is not subgame perfect. a) (10 points) Cat A B Dog Dog C E 4, 4) (1,3) (2,9) (9,2) b) (10 points) FB L Twitter Twitter A C D LinkedIn LinkedIn 900 175 250 350 400 250 E F G/ H 500 300 425 200 150 300 125 175 -50 300 150 225