Before conducting the needs assessment, it may be helpful to consult census data available in geographical units to learn more about the population being studied. This is an example of use of .

Secondary data

Explanation:

Secondary data -

It refers to the data , which is organised or gathered by the someone apart from the user , is referred to as the secondary data .

The common source of information of the secondary data are -

information from the government departments , some previous record or data which is used for the research purpose .

Hence , from the given information of the question ,

The correct answer is Secondary data .  

all cities have a governor

all cities are in states or provnies then country

all cities have people

difference

some are rich

some are poor

some are average