Which of the following is NOT a common sign of a bidding anomaly?

The correct choice highlights that having multiple contractor bids with diverse offerings is not typically considered a sign of bidding anomalies. This scenario often indicates a healthy competitive environment where numerous bidders are providing varied solutions or proposals, which can actually enhance the integrity of the bidding process.

In contrast, options such as a limited number of bidders responding, high similarity between the winning bids and the products offered by contractors, and unexplained changes in bid specifications often point to potential discrepancies or irregularities in the bidding process. When only a few bidders participate, it can indicate collusion or a lack of competition, which undermines fair pricing. Similarly, high similarity in bids may suggest that bidders are not competing genuinely or that they have coordinated their responses. Unexplained changes in specifications could indicate attempts to favor certain bidders or manipulate the outcomes of the bidding process. Each of these factors can signal that fraud or unethical practices may be occurring, whereas diverse offerings suggest a robust competitive landscape.