Which of the following is a vector quantity?

Electric field

The correct answer is option 3. Electric field.

Electric field is a vector quantity. A vector quantity is a quantity that has both magnitude and direction. In the case of an electric field, it has both magnitude (which determines the strength of the field) and direction (which indicates the direction in which a positive test charge would move if placed in the field).

Electric charge, electric flux, and electric current are scalar quantities, as they are described only by their magnitude and not by a specific direction.