Can a person be “promoted” or “demoted” to another social class?

Yes but It depends on which country you are talking about since certain countries have different "social classes".

Explanation:

When a person is promoted they are ranked above other's that are lower in rank below them(obviously). And when a person is demoted they are taken down the social class pyramid and be of lower rank to people above them.  People on top of the social class pyramid are considered very valuable assets and can not be demoted especially if it's like a heritage based social order( which is found in most religious countries that have a government known as a Theocracy).

where is the rest of the question. this isn't making sense. can you upload a picture of the question?