Which of these characterizes a cross-sectional study of development?

(a) Researchers compare people from several cultures.

(b) Researchers compare one group of people at several times as they grow older.

(c) Researchers compare people of different ages, at the same time.

(d) Researchers examine many aspects of behavior, for one group of people at one point in time.

When we say cross-sectional study, then we are recording data of population of interest in a specific point of time. By doing this, we can make inferences about something that occurs because we studied different ages, and we can infer that the changes were not attributed to passing of time.

Source: https://www.verywellmind.com/what-is-a-cross-sectional-study-2794978