Phase II clinical trials primarily involve:

• A. Phase II: investigators give the drug to larger groups of people to get preliminary indication of its effectiveness and to do more assessments of safety
• B. Phase II: tests safety in a few people only
• C. Phase II: determine whether the drug is effective and how it compares with proven treatments
• D. Phase II: monitor long-term safety in the general population

Answer: (A)

Phase II trials expand on early safety findings to look for preliminary effectiveness and to refine dosing, using a larger group of patients with the disease. They’re designed to see whether the drug shows real signals of activity and to gather more information about safety at the therapeutic dose, which helps decide whether to move on to the larger, more definitive Phase III studies. These trials typically involve more participants than Phase I, and may include dose-ranging and sometimes randomized comparisons, but they’re not the final test of efficacy nor a long-term safety check in the general population. The descriptions in the other options fit Phase I (safety in a few people), Phase III (definitive efficacy and comparisons in large populations), and Phase IV (long-term safety after approval).