Electron Flow in Metal Conductors

Steps:

• Charge carriers in metals are free electrons, not protons.
• Electrons move from the negative battery terminal (high electron potential) to the positive terminal (low electron potential).
• This flow constitutes electric current in the conductor.
• Option D matches this direction and particle type.

Why D is correct:

• Electrons, negatively charged, flow toward the positive terminal due to electrostatic attraction (Coulomb's law).

Why the others are wrong:

• A: Protons are fixed in atomic nuclei and do not flow in conductors.
• B: Electrons flow from negative to positive, not positive to negative.
• C: Protons do not move; direction is also incorrect for electrons.

Final answer: D