California
Code of Civil Procedure CCP § 2019.010
Any party may obtain discovery by one or more of the following methods:
(a) Oral and written depositions.
(b) Interrogatories to a party.
(c) Inspections of documents, things, and places.
(d) Physical and mental examinations.
(e) Requests for admissions.
(f) Simultaneous exchanges of expert trial witness information.