Which choice most logically completes the text?

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Some studies can be done well with relatively little money. For example, a marketing study simply trying to identify the average amount customers spend per transaction at an online retailer has a straightforward central question that doesn't require many years of data collection. But it is much more expensive to conduct a longitudinal study like the Household, Income and Labour Dynamics in Australia Survey (HILDA), which looks at data for 25,000 people in Australia to find trends in economic well-being that can take a long time to develop. This requires lots of funding because _____

marketing studies are not likely to require data m very many individuals.

data from 25,000 people may not be enough to veal significant trends in economic well-being.

long-term trends in economic well-being are hard to find without collecting data over many years.

long-term trends in marketing can be found without examining many years of data.