Step 1: Concept
Post-marketing surveillance is critical for identifying rare adverse effects that did not appear during clinical trials.
Step 2: Meaning
This field involves the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.
Step 3: Analysis
Pharmacoeconomics deals with costs, and Pharmacogenomics deals with genetic influences on drug response. Pharmacovigilance is the specific term for the ongoing monitoring of drug safety in the general population.
Step 4: Conclusion
The practice of monitoring safety after a drug reaches the market is known as Pharmacovigilance.
Final Answer: (C)