Answer:
When members of the lower class are unable to achieve symbols of success via conventional means, they feel anger, frustration, and resentment. These feelings are collectively referred to as strain.
Step-by-step explanation:
The natural tendency of living beings is to associate and disassociate according to their interests. When these interests are not common, then we have a strain. It's the process to counter-attack a situation where a social group cannot achieve their desires or rights. A social condition that is almost turning into a conflict.