California Code, Education Code - EDC § 51939

(a) A pupil may not attend any class in comprehensive sexual health education or HIV prevention education, or participate in any anonymous, voluntary, and confidential test, questionnaire, or survey on pupil health behaviors and risks, if the school has received a written request from the pupil's parent or guardian excusing the pupil from participation.

(b) A pupil may not be subject to disciplinary action, academic penalty, or other sanction if the pupil's parent or guardian declines to permit the pupil to receive comprehensive sexual health education or HIV prevention education or to participate in anonymous, voluntary, and confidential tests, questionnaires, or surveys on pupil health behaviors and risks.

(c) While comprehensive sexual health education, HIV prevention education, or anonymous, voluntary, and confidential test, questionnaire, or survey on pupil health behaviors and risks is being administered, an alternative educational activity shall be made available to pupils whose parents or guardians have requested that they not receive the instruction or participate in the test, questionnaire, or survey.