Final answer:
In an FHSS system using 10 frequencies, if narrowband interference impacts one frequency, the spread spectrum signal will remain mostly intact, and the affected data can be retransmitted on another frequency.
Step-by-step explanation:
In a frequency-hopping spread spectrum (FHSS) communication system that uses multiple frequencies for data transmission, if narrowband interference occurs at only one of the in-use frequencies, a couple of resilience mechanisms come into play. Primarily, the signal will continue to be transmitted over the remaining uninterfered frequencies, ensuring that the majority of the data transmission process remains intact. Additionally, any lost data on the interfered frequency can be retransmitted on one of the other frequencies not facing interference. This is possible because FHSS systems are inherently designed to handle interference and provide reliable communication even in environments with potential signal disruptions.