Choose the correct option from the following.

(A) The internal resistance of a cell depends on its distance between electrodes and on the area of the electrodes.
(B) The emf of a cell is measured when it is used in series in an electrical circuit carrying current I.
(C) If a cell of emf E and of internal resistance r is providing current I through a resistance R then the potential difference across the cell is $V = I(R +r)$.
(D) The emf of a cell is 1 V, if 1 J of work is done by the cell to drive 1 C of charge in the whole circuit.

Choose the correct answer from the options given below:

(A) and (D) only

The correct answer is Option (4) → (A) and (D) only

(A) Correct — Internal resistance depends on electrode separation, area, and electrolyte properties.

(B) Incorrect — EMF is measured when no current flows (open circuit), not when cell is in series carrying current.

(C) Incorrect — Terminal voltage $V = E - Ir$, not $I(R+r)$.

(D) Correct — EMF = work done per unit charge = $1\ \text{J}/1\ \text{C} = 1\ \text{V}$.

Correct statements: (A), (D)