When high school students from the lower social classes are directed toward technical schools, regardless of their ability, this is known as
a mainstreaming.
b social integration.
c the hidden curriculum.
d social placement.

social placement

Explanation:

Social placement is when people are funneled into a society's various positions at a mass scale. The entire lower social class is funneled into a class the doesn't fit all of them because of their parent's amount of money.

Happiness is a matter of perspective, hence, it will differ to different range of ages. Older people tend to value intangible things like time with family, relationships, job satisfaction and contentment in life. For younger people, they are more into the present and short-lasting euphoria like acquiring gadgets, gifts and the like. However, there could be other deep reasons like love and music and making their parents proud.