What type of data is collected by observing many subjects at the same point in time?

The correct answer is that the type of data collected by observing many subjects at the same point in time is known as cross-sectional data. This kind of data involves taking a snapshot of a particular variable or set of variables across multiple subjects simultaneously. It allows for comparisons between different subjects at a single point, making it useful for understanding variations and trends in that moment without considering how those subjects may change over time.

In contrast, time series data involves observations collected over time, focusing on a single subject or variable at different time intervals. Longitudinal data, on the other hand, tracks the same subjects across multiple time periods, capturing changes and developments over time. Statistical data is a more general term that encompasses various types of data analyses but does not specifically refer to the method or timing of collection like the other terms do.

By recognizing the characteristics of these types of data, it's easier to see why cross-sectional data is the appropriate choice when the focus is on a collective observation at one moment.