If a psychologist was interested in studying the stability of IQ scores over time, she should use the method of data collection by following the same group of participants over an extended duration.

The answer for the blank space is: cross-sectional.

Explanation:

The cross-sectional method of data collection is mostly employed developmental psychology research; the method—which is used to conduct studies on categories of people who have different interests, but have similar characteristics—is used to collect data of observations taken on regions, organizations, or groups of individuals at a certain point in time, or over a period of time.

answer; /// the answer to the first question is (b) it began when people first deliberately seeds; /// and (d); // it gave people a steady food supple for the first time;