Final answer:
Higher socioeconomic parents use educational advocacy to help their children get enrolled in higher-track classes, thereby maintaining educational inequalities.
Step-by-step explanation:
The mechanism by which higher socioeconomic parents help their children become enrolled in higher-track classes is a) Educational advocacy. Parents with higher socioeconomic status often possess the resources and knowledge to advocate for their children's education. This may involve hiring tutors, engaging educational consultants, and leveraging social capital to ensure that their children are placed in classes that will provide them with the greatest advantage, such as advanced or honors classes, thereby perpetuating existing inequalities within educational tracking systems.