The Government of India conducts a census every ten years. The method of research used in this process is

A decennial census enumerating the whole population is the survey method.

A case study examines a single unit in depth, not a nation.

Developmental research traces change across time or age.

Experimental research manipulates variables under control.

The census gathers standardized data from every household.

India's census has been conducted decennially since 1881.