At any given point in the electric field region, the electric flux (i.e. the number of field lines per unit area) determines the intensity of the field. The points in the region where the flux is more are associated with strong electric fields.

For a given area, field lines are dense and equal in number at point A and C.

Therefore, E_A = E_C

And at point B, the field lines are far away which indicates lesser intensity of electric field at point B than at point A and C.