An AI system generates personalized pricing for e-commerce customers. Regulatory investigators find that older customers consistently receive higher prices for identical products. The company argues the model uses purchase history and browsing behavior, not age, as inputs. What concept BEST describes the mechanism by which age discrimination could still occur?

B is correct because even without using age directly, features like browsing patterns, device type, or purchase history may be strongly correlated with age and cause the model to produce age-discriminatory outcomes. This is proxy discrimination or indirect discrimination: a facially neutral variable produces protected-class-based disparate impact. Direct discrimination (A) would require age to be an explicit input. Statistical discrimination (C) could be a strategy, but the scenario describes an unintentional correlation. Intentional redlining (D) implies deliberate targeting, which is not established by the facts.