Which of the following PBMs is associated with Express Scripts?

The correct choice is associated with Express Scripts, a pharmacy benefit manager (PBM) that plays a significant role in the management of prescription drug benefits. Express Scripts, often abbreviated as ESI, is known for its ability to negotiate drug prices, manage formularies, and provide various services to employers and health plans. The association with ESI is direct, as this abbreviation is widely recognized in the industry and explicitly refers to Express Scripts itself.

In contrast, the other options represent different companies or PBMs that operate independently of Express Scripts. Prime Therapeutics, for instance, is another PBM that has its distinct operations and partnerships. CVS Health is a larger healthcare entity that includes its PBM services but is not synonymous with Express Scripts. Transparent Rx also functions within the pharmacy benefit space but does not have the same direct connection to Express Scripts. Thus, the identification of ESI as the correct choice stems from its established reputation and direct relationship with Express Scripts, making it the most accurate answer among the provided options.