The solutions to many problems involving electric fields are simplified by making use of equipotential surfaces. An equipotential surface is a surface:
1. On which the potential is same everywhere
2. The movement of charge over such a surface would require no work
3. The tangential electric field is zero
4. The normal electric field is zero
Which of the above statements are correct?

A. 1, 2 and 3 only

B. 1, 2 and 4 only

C. 2, 3 and 4 only

D. 1, 2, 3 and 4

Answer: Option A