Cal. Code of Civil Procedure § 2028.050

(a) A party who objects to any question on the ground that it calls for information that is privileged or is protected work product under Chapter 4 (commencing with Section 2018.010) shall serve a specific objection to that question on all parties entitled to notice of the deposition within 15 days after service of the question. A party who fails to timely serve that objection waives it. (b) The party propounding any question to which an objection is made on those grounds may then move the court for an order overruling that objection. This motion shall be accompanied by a meet and confer declaration under Section 2016.040. The deposition officer shall not propound to the deponent any question to which a written objection on those grounds has been served unless the court has overruled that objection. (c) The court shall impose a monetary sanction under Chapter 7 (commencing with Section 2023.010) against any party, person, or attorney who unsuccessfully makes or opposes a motion to overrule an objection, unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust.