Final answer:
The question of how children earned money at the supermarket is not directly answered by the provided options. Historically, children from working families often took on various jobs, which could include informal tasks helping supermarket customers. Today, working-class students might take jobs like stocking shelves to contribute to their family income.
Step-by-step explanation:
How the children earned money at the supermarket is not specified amongst the options provided; however, it's important to note that children from working-class families often took on various jobs to support their households. In historical contexts, they might even work in difficult and dangerous conditions, such as in mines or factories, as John Spargo highlighted the harsh realities faced by young boys. In more contemporary settings, students might look for part-time jobs like stocking shelves at a supermarket to contribute financially to their families, a situation that could impact their school performance due to exhaustion and lack of resources.
None of the provided options directly reference a common job at a supermarket that would involve children directly earning money. However, outside the supermarket scenario, children found ways to earn money through other means, such as piecework at home, selling matches, or working in family businesses. Individual initiative, such as helping people carry bags to their cars, could also be a way for children to earn money, although this is not typically a sanctioned job at most supermarkets.