How do certain insurers improve their pricing negotiations with hospitals?

The correct choice highlights that insurers can leverage their influence in pricing negotiations with hospitals by securing a larger share of the hospital's book of business. When an insurer brings a significant volume of patients to a hospital, they become a valuable partner for that institution. This relationship allows the insurer to negotiate better terms, as hospitals may be more inclined to offer favorable pricing to ensure a steady flow of patients.

Insurers who can promise more business are often in a stronger position to negotiate rates that reflect their larger patient base. This volume gives them leverage because hospitals benefit from higher occupancy rates, which can lead to better overall financial performance. Therefore, the strategy of fostering a larger share of the hospital's business is a practical approach to enhancing negotiation strength regarding pricing.

In contrast, limiting the number of insured individuals is generally not beneficial for negotiating better terms. Focusing on smaller hospitals may not provide the same leverage since these establishments may lack the resources to negotiate competitively. Lastly, increasing hospital charges does not inherently improve the insurer's negotiation position—it often has the opposite effect by raising costs for patients and insurers alike.