Opinion sampling may be necessary for the following reasons except________

Analyze the question: This is an "except" question. Three options give valid reasons for opinion sampling, and one does not. We are looking for the odd one out.

Concept: Opinion sampling (an opinion poll) means asking a representative group of people what they think about an issue, a leader, a policy or a party. It is used to:

• find out what people generally think on an issue
• measure the popularity or political strength of parties and candidates
• guide government on public feeling about policies
• encourage public discussion of national issues

Option by option:

• A. Aggregating popular thinking and standpoint on a subject matter. This is the main purpose of opinion sampling, so it is a valid reason.
• B. Preparing public expenditure. A budget is prepared from revenue estimates, ministry needs, economic data and government priorities. Opinion polls are not the tool for drawing up expenditure figures, although public views may sometimes inform priorities. This is the weakest link to opinion sampling.
• C. Evaluating the political strength of a party. Pre-election polls do exactly this, so it is valid.
• D. Inspiring public reasoning on population census. Polls can raise awareness and debate on national issues such as the census, so it is acceptable as a reason.

Answer: B is the exception. Preparing public expenditure is a technical, financial planning activity, not a purpose of opinion sampling.

Tip: In "except" questions, first confirm the options that clearly match the definition (here A and C), then pick the one that belongs to a different process. "Budget/expenditure" is about finance, not public opinion.