If there's nothing else connected to the battery except the 3-ohm resistor, then the question is defective and the correct answer is not on the list.
With 12v connected across the resistor, the current through the resistor is
I = (E/R) = (12/3) = 4 Amperes.
The power generated inside a resistor is
P = (E x I) = (12v) x (4 A) = 48 watts
