A discount retailer facing a consumer boycott due to poor working conditions will most likely face an adverse impact on revenues.

Adverse impact on revenues (C): A consumer boycott directly affects the retailer's sales and revenues. When consumers choose not to purchase from the retailer due to poor working conditions, the retailer experiences a decrease in sales, which negatively impacts its revenue stream. This can also affect the retailer's market share and brand reputation.

Significant liabilities (A): While poor working conditions might eventually lead to liabilities such as legal fines or compensation claims, the immediate effect of a consumer boycott is more directly felt in reduced revenues.

Greater operating costs (B): Poor working conditions can indirectly lead to higher operating costs due to potential inefficiencies, higher turnover, or the need to improve conditions in response to negative publicity. However, the primary immediate impact of a consumer boycott is on revenues.