The correct answer is A) mathematics.
The field of knowledge that the shopkeeper relied on Bronze Edge advancements to keep track of sales was mathematics.
Mathematics was essential to keep tracks of purchases and sells in order to have better control and organization of the operation in the business. It was such as the first steps of accounting to better register the goods that were sold and does not have any kind of losses.
The other options of the question were B) agriculture, C) architecture and D) city planning.