
The harmonic frequency refers to the resonant frequency that is an integral multiple of the fundamental frequency, harmonics are usually simple sinusoidal oscillation at a single frequency. where as Resonance frequency are frequencies that are not necessarily sinosudal or integral multiple of fundamental frequency and it may have complex oscillations made up of multiple harmonics ~
It's like if you play a piano with a single key, it will show harmonic frequency, but if you use multiple keys at a time it may show Resonance.
Yes, the correct answer is D.
Including this information at the end of the article helps the reader understand what happened after the president's speech.
This information does explain how some of the transfer of power will proceed, but that is not why the information comes at the end of the article. Only answer D explains this statement's presence at the end of the article.
You have to answer whatever is written in Nicola's letter and once you answer that make sure you capitalize and put a period at the end. <span />