Wait I know the answer but let me just make sure it is the right answer
The answer to this question is <span>Longitudinal Study
The main purpose of this type of study is to find out whether a certain variable will give different response if the time factor is change.
Examples of this time of study would be: a sudy to find out how long it need for a certain viruss to develop if it got injected since early age.</span>
Answer:
it caused the value of their money to drop, as demand for gold and silver rose
Explanation:
Yams and cassava, hope it helps