Answer:
C. It is caused by flowing negatively charged particles.
Step-by-step explanation:
Current electricity is caused by flowing negatively charged particles. The negatively charged particles that are responsible for the flow of electricity are called electrons.
The force is equal at all points in the field as the field lines are parallel in a uniform field. So, negatively charged particles will move in the opposite direction to the current.
Hence, the correct answer is "C. It is caused by flowing negatively charged particles."