Final answer:
The remote pilot in command (PIC) is responsible for determining the performance of a small unmanned aircraft under 14 CFR part 107.
Step-by-step explanation:
According to 14 CFR part 107, which pertains to the operation of small unmanned aerial systems (UAS) in the United States, the remote pilot in command (PIC) is responsible for determining the performance of a small unmanned aircraft. This involves an understanding of the aircraft's capabilities as well as the environmental factors that could impact its performance during flight operations. The remote pilot in command must ensure that the UAS can safely complete the flight as planned before conducting the operation.