Indirect standardization is used when study-specific age-specific rates are unstable or unavailable. Which approach describes how it is performed?

• A. Use study population's crude rates adjusted by age
• B. Apply standard population's age-specific rates to the study population's age distribution to compute expected cases
• C. Directly compare age-specific rates between populations
• D. Apply standardization by adjusting all rates to a common scale

Answer: (B)