If you carry heavy weights in your hands, how will this affect the natural frequency at which your arms swing back and forth?

In principle, no impact. However your arms are not straightforward pendulums, on the grounds that they have mass, grating, and the length changes as indicated by the weight conveyed Hence when all is said in done, the heavier the weights the lower your arms will swing. I trust the appropriate response will help you.

Letter a, because when there are unlike charges they will always attract to each other.