What Does It Mean When a Medication Is Sold Under

What does it mean when a medication is sold under patent?

A) The medication can only be marketed by the pharmaceutical company that manufactured it.
B) The medication can be marketed by pharmaceutical companies that did not manufacture it as long as they use a different trade name from the pharmaceutical company that made the medication.
C) The medication can be marketed by pharmaceutical companies that did not manufacture it as long as they use the same trade name as the pharmaceutical company that made the medication.
D) The medication can be marketed by any pharmaceutical company without restrictions placed on its trade name.