Final answer:
The Remote Pilot in Command is responsible for determining the performance of a small unmanned aircraft according to 14 CFR Part 107.
Step-by-step explanation:
According to 14 CFR Part 107, the responsibility for determining the performance of a small unmanned aircraft falls upon the Remote Pilot in Command (Remote PIC). This means that the Remote PIC must ensure that the small UAS is safe for operation and must be familiar with all aspects of its performance before flying. It is essential that the Remote PIC evaluates conditions such as the operating environment, potential hazards, and the performance capability of the aircraft.