Which of the following describes resonance frequency in regards to a piano

Resonance frequency in a piano refers to the natural frequency at which the strings of the piano vibrate and produce a strong and clear sound. This frequency is determined by the length, tension, and mass of the strings, as well as the construction of the piano's soundboard and frame. Playing a note on the piano that matches its resonance frequency will result in a powerful and sustained sound due to the strings vibrating at their maximum amplitude.