Michael and Scarlett cannot agree on the price he will pay her to manage his hotels in the third ...

Michael and Scarlett cannot agree on the price he will pay her to manage his hotels in the third year of their contract. They agree to a provision stating that the price will be reasonable.. This provision is ________________. Parties should never include such a provision in a contract unless _____________________.
 a. ambiguous/ they are sure they will be able to reach an agreement later.
  b. vague/ they are sure they will be able to reach an agreement later.
  c. ambiguous/ they would not mind if the other side's interpretation prevails in litigation
  d. vague/they would not mind if the other side's interpretation prevails in litigation