Which action would likely be considered discriminatory under the Commissioner's Regulations?

The action of posting a sign indicating a preference for female renters is deemed discriminatory because it directly expresses a bias based on gender, which is a protected characteristic under fair housing laws. These laws are designed to prohibit discrimination in housing-related activities based on various factors, including race, color, religion, sex, nationality, familial status, and disability. By explicitly stating a preference for one gender over another, this action violates the principle of equal opportunity in housing and could lead to exclusion or unfair treatment of male renters.

In contrast, refusing to sign a selling agreement, offering discounts to first-time homeowners, and advising clients on property values do not inherently suggest discrimination against a specific group. The refusal to sign a selling agreement may involve various legitimate reasons unrelated to discrimination, while providing discounts is often a marketing strategy aimed at encouraging homeownership rather than indicating bias. Similarly, advising clients on property values pertains to professional practice and does not involve discriminatory intent or action. Thus, only the sign indicating a preference for female renters clearly falls into the realm of discriminatory practices as defined by the Commissioner's Regulations.