(a) Grounds separately stated Each ground of demurrer must be in a separate paragraph and must state whether it applies to the entire complaint, cross-complaint, or answer, or to specified causes of action or defenses. (b) Demurrer not directed to all causes of action A demurrer to a cause of action may be filed without answering other causes of action. (c) Notice of hearing A party filing a demurrer must serve and file therewith a notice of hearing that must specify a hearing date in accordance