Answer:
b. electrons drift slowly toward the positive end of the wire
Explanation:
Motion of electrons constitutes current. According to Ohm's law, the current in the wire is directly proportional to the potential difference across the two ends of the wire.
I ∝ V
⇒V = I R
When potential difference is put, the electrons towards the positive end. Thus, option b is correct.
The answer is "friction and air resistance" gravity does some of the work by keeping the object from floating away, but friction and air resistance does the biggest part. Friction is how rough the ground it meaning on tile, dirt, grass, etc... that would slow down the object and air resistance is the gravity pushing on the object also making it stop.
Hope this helps!