Hello. You did not submit the article to which this question refers, which makes it impossible for it to be answered accurately. However, I will try to help you in the best possible way.
It is only possible to find the cause and effect relationship in the article, after reading it. In that case, you should look in the text for the moment when a situation happens as a result of another situation. Therefore, the text must show an element (cause) which, when it happened, caused the creation of another element (effect).
An example of a challenge facing the American people during the late 20th and early 21st century is public education. The American democracy depends on an educated and well informed citizenry.