Well I would go with "2"...anyone with another employee could work on diversity. But I am sure that is not what you were asking.
Title VII covers employers with more than 15 employees. Even then, an employer is not required to have a formal diversity policy....but rather just be able to prove that they do not illegally discriminate based on race, religion, etc. We use the standard EEO policy statement. The following is a link to an EEOC Compliance Manual on Race.....I suggest you read the part titled "Diversity and Affirmative Action" http://www.eeoc.gov/policy/docs/race-color.html#VIC One specific quote "The Commission encourages voluntary affirmative action and diversity efforts to improve opportunities for racial minorities in order to carry out the Congressional intent embodied in Title VII.(115) Further, the Commission believes that “persons subject to Title VII must be allowed flexibility in modifying employment systems and practices to comport with the purposes” of the statute.(116) However, employers are cautioned that very careful implementation of affirmative action and diversity programs is recommended to avoid the potential for running afoul of the law."
i think a company with as few as two employees could have a diversity program. i encourage you to read this research from harvard while you are developing one: http://www.wjh.harvard.edu/~dobbin/cv/working_papers/aapracticesFinalProof.pdf