Which of the following is characterized as a major stage in drug development?

Regulatory approval is a critical stage in drug development because it involves the formal review process by government agencies, such as the FDA in the United States, which evaluates the safety and efficacy of a new drug before it can be marketed to the public. This stage is essential to ensure that the product meets the required standards and regulations for public health, setting it apart from other activities such as market analysis, product launch, and marketing strategy development, which, although important for the commercial success of the drug, do not directly contribute to the scientific and safety validation of the drug itself. Regulatory approval is often considered one of the last and most significant hurdles in the drug development pathway, representing a culmination of preclinical and clinical testing data that demonstrates the drug's effectiveness and safety profile. Only after passing this stage can a drug move forward to be available for prescription and use by healthcare providers and patients.