AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(B) Uniform and parallel to the axis
The field lines inside a solenoid are parallel straight lines, indicating the magnetic field is uniform (same at all points) inside it.
The source passage explicitly states: "The field lines inside the solenoid are in the form of parallel straight lines… the field is uniform inside the solenoid." Examiners expect option (B) with a one-line justification. Options C and D are incorrect; the field is NOT zero (A) nor strongest at the ends (C) inside a long solenoid.