What caused Norrie to get grounded?

Norrie got grounded because she received a D on her history test. This reflects the expectations that her parents likely had regarding her academic performance. In many narratives, getting a poor grade can lead to consequences at home as it may indicate a lack of effort or focus on her studies. The grounding serves as a way for her parents to encourage her to take her education more seriously and to motivate her to improve her grades in the future.

The other options present situations that could potentially lead to being grounded, but they do not carry the same weight as a poor academic performance. Missing a practice might be a disappointment, but it’s often associated with extracurricular activities rather than academic obligations. Losing riding gear could be seen as careless, but it’s unlikely to have the same serious implications as underperformance in school. An argument with her parents might lead to temporary tension or conflict in the household, but it does not necessarily result in punishment like being grounded unless it was particularly severe. Thus, the D on her history test stands out as a more significant reason for her being grounded.