Final answer:
The requirement 'The system should provide function converting measure units' is categorized as a System requirement. It defines a specific functionality of the system related to unit conversion, with metric system being based on powers of 10 and U.S. customary system having unrelated conversion factors.
Step-by-step explanation:
The requirement "The system should provide function converting measure units" falls under C. System requirements. System requirements specify what the system should do, and this particular requirement is about a specific functionality that the system must provide.
When discussing the topic of converting measurement units, it is essential to note that in the metric system, unit changes typically use powers of 10 for conversion (not powers of 2 as mentioned in the mistaken information given), which makes them relatively straightforward. Conversely, the U.S. customary system involves unit conversions that have unrelated and specific conversion factors for each unit change, which can make conversions more complex.