After the jurors have retired to consider their verdict, the court shall discharge them from the cause when:
(a) their verdict has been received;
(b) on the expiration of such time as the court deems proper, if the court finds there is no reasonable probability that the jurors can agree on a verdict; or
(c) a necessity exists for their discharge.
The court may in any event discharge the jurors from the cause if the prosecuting attorney and the defendant consent to the discharge.