Important of Sample Survey​

Surveys are useful in describing the characteristics of a large population. No other research method can provide this broad capability, which ensures a more accurate sample to gather targeted results in which to draw conclusions and make important decisions.

Importance:

Advantages of Sample Surveys compared with Censuses: Reduces cost - both in monetary terms and staffing requirements. Reduces time needed to collect and process the data and produce results as it requires a smaller scale of operation. (Because of the above reasons) enables more detailed questions to be asked.

i think the answer would be b.