Why might primary data be unsuitable for studying long-term changes?

• A. It can be hard to study temporal changes.
• B. It provides seamless time series data.
• C. It automatically records historical trends.
• D. It is always archived.

Answer: (A)

Studying long-term changes needs data that spans many years so patterns over time can be seen. Primary data is collected directly for a specific study and is often gathered at one time or over a short period. Because of that, it isn’t automatically a long-running series, and building a long-term record would require repeating measurements across many years, which is usually costly and time-consuming and can introduce inconsistencies. So primary data isn’t well suited for tracing long-term changes. The other statements don’t fit because primary data doesn’t inherently provide a seamless time series, doesn’t automatically record historical trends, and isn’t necessarily archived unless you deliberately preserve it.