Final answer:
Parents of higher-tracked students generally support tracking due to perceived benefits, while lower-tracked students' parents oppose it because of concerns about inequality and self-fulfilling prophecies.
Step-by-step explanation:
Decisions about whether to implement tracking in non-tracked schools, or whether to de-track schools that use ability grouping, are typically quite controversial. In this context, parents of students in the higher tracks support tracking, as they may believe their children benefit from being with students of similar ability and potentially receiving more individual attention from teachers. On the other hand, parents of students in the lower tracks tend to oppose tracking, often due to concerns highlighted by conflict theorists about such systems creating self-fulfilling prophecies and perpetuating inequalities. Therefore, the statement to complete the given sentence would be: parents of students in the higher tracks c) support tracking; while parents in the lower tracks d) oppose tracking.