Please answer a and b by tree diagram. Thank you

2) (a) Model a kidnapping scenario with an extensive form game that has a non-subgame perfect Nash equilibrium in which the ransom is paid. (b) Model a kidnapping scenario with an extensive form game that has a subgame perfect Nash equilibrium in which the ransom is paid. (c) Explain the difference in your assumptions about outcomes that justifies the difference your payoffs between your games (a) and (b)