If you can (english)
when charles was younger, he was considered one of the city's best high school teachers. now he is in his 70s and instead of teaching students, he now spends his days with his grandchildren. his grandchildren love him, but some members of society consider him to be nonproductive. what is this an example of?
a. bias
b. ageism
c. age stratification
d. all of the above

The answer seems to be indeed letter D. all of the above.

Explanation:

Having a bias toward something means showing preference for it in detriment of something else. The word "bias" indicates that a person likes or dislikes something very much when compared to something else. Thus, they can be biased against something, or biased in favor of/toward something. It is possible, for example, for people to be biased against the elderly, seeing them as useless since they no longer contribute to society by working.

The description and example above also work for ageism. Ageism is a form of bias. It is the action of judging people according to their age.

Age stratification is the action that leads to ageism. It is the division of society into hierarchical categories according to age. In Western countries, those who are very young or very old are seen as inferior, as incompetent.

Therefore, all the options can refer to the example provided in the question. An old man is being judged as nonproductive due to his age and the fact that he no longer works.

the correct answer is the first one.