California Code, Code of Civil Procedure - CCP § 2033.040

(a) Subject to the right of the responding party to seek a protective order under Section 2033.080, any party who attaches a supporting declaration as described in Section 2033.050 may request a greater number of admissions by another party if the greater number is warranted by the complexity or the quantity of the existing and potential issues in the particular case.

(b) If the responding party seeks a protective order on the ground that the number of requests for admission is unwarranted, the propounding party shall have the burden of justifying the number of requests for admission.