Question

what is the eventual focus of understanding the underlying mechanism behind static effects, built upon in lesson 3 and later lessons? the movement of charges. the color of objects. the density of materials. the mass of particles.

Explanation:

Static effects are related to electric - charge interactions. The movement of charges is fundamental to understanding the underlying mechanism of static effects. Color, density, and mass of particles are not directly related to the core of static - effect mechanisms.

Answer:

A. The movement of charges.