Within 21 days of the service thereof any such owner who desires to assert any objection or defense to the taking or damaging of his property or to the jurisdiction of the court to hear the case, and to make his election to proceed with either the appointment of commissioners or the empanelment of a jury, shall file (i) his answer and grounds of defense designating the property in which he claims to be interested, (ii) the grounds of any objection or defense to the taking or damaging of his property or to the jurisdiction of the court to hear the case, and (iii) his election to proceed with either the appointment of commissioners or the empanelment of a jury for the determination of just compensation.