Cal. PROB § 15601

(a) A person named as trustee may in writing reject the trust or a modification of the trust. (b) If the person named as trustee does not accept the trust or a modification of the trust by a method provided in subdivision (a) of Section 15600 within a reasonable time after learning of being named as trustee or of the modification, the person has rejected the trust or the modification. (c) A person named as trustee who rejects the trust or a modification of the trust is not liable with respect to the rejected trust or modification.