Which of the following statements are correct?

(A) The emf of a cell depends on the internal resistance of the cell.
(B) The emf of a cell depends on the external resistance of the circuit.
(C) It is easier to start a car engine on a warm day than on a cold day.
(D) The temperature coefficient of resistance ($α$) of carbon is negative.

Choose the correct answer from the options given below:

(C) and (D) only

The correct answer is Option (2) → (C) and (D) only

Analysis of statements:

(A) The emf of a cell depends on the internal resistance of the cell → False. EMF is determined by chemical composition, not internal resistance.

(B) The emf of a cell depends on the external resistance of the circuit → False. EMF is independent of external resistance.

(C) It is easier to start a car engine on a warm day than on a cold day → True. Battery performance and fuel vaporization are better at higher temperatures.

(D) The temperature coefficient of resistance (α) of carbon is negative → True. Carbon is a negative temperature coefficient (NTC) material.

Correct Statements: (C) and (D)