As it is with traditional pharmacies, online drugstores rely on prescriptions to be successful, since it is primarily prescriptions that attract the customers, who then also buy other health-related items.
A. As it is with traditional pharmacies, online drugstores rely on prescriptions to be successful
B. As with the case of traditional pharmacies, online drugstores rely on prescriptions to have success
C. As is the case with traditional pharmacies, prescriptions are the cornerstone of a successful online drugstore
D. As traditional pharmacies, so online drugstores rely on prescriptions to be successful
E. Like traditional pharmacies, the cornerstone of a successful online drugstore is prescriptions