What is the relationship between the electric field and the lines of force?

I- The lines of force begin in positive charges and end in negative charges.
II- The tangent to the electric field line that crosses any point in space denotes the direction of the electric field there.
III- The magnitude of the electric field at any point is proportional to the number of lines per unit of surface perpendicular to these lines.
IV- The lines of force are always parallel and equidistant.
a) I and II are correct.
b) II and III are correct.
c) III and IV are correct.
d) I and III are correct.