Competitive pressures from buyer bargaining power weaken when:

The correct answer is based on the understanding of buyer bargaining power's relationship with switching costs. When the costs of switching to substitutes are high, buyers are less inclined to leave their current supplier for alternatives. This creates a scenario where the seller maintains greater control over pricing and contractual terms because the buyer faces significant hurdles if they choose to switch.

High switching costs can stem from factors like proprietary technology, brand loyalty cultivated through significant investments, or even the potential loss of customized services that have been tailored to the buyer's needs. Thus, as switching becomes more difficult or costly, the leverage of buyers diminishes, cutting into their ability to negotiate lower prices or demand better quality or services.

In contrast, a small number of buyers generally increases buyer power because they can influence prices more readily, slow-growing demand typically leads to excess supply, and intense competition among sellers can drive prices down and empower buyers. Therefore, high switching costs are pivotal in reducing buyer bargaining power, maintaining a favorable position for sellers.