According to newton’s first law of motion, when will an object at rest begin to move? when its inertia decreases to zero when an unbalanced force acts upon it when the action and reaction forces are equal when two equal and opposite forces act upon it

An object at rest will begin to move when b. an unbalanced force acts upon it.

It is basically saying when a force is applied to an object, it will move.

Hope this helps!

The correct answer for this question would be B. An unbalanced force acts upon it. 

Non metal is an element or substance that is not a metal metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivitymetalloid is an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. they are electrical semiconductors.