A Monatomic Ideal Gas Undergoes an Isothermal Expansion at 300

A monatomic ideal gas undergoes an isothermal expansion at 300 K, as the volume increased from to The final pressure of the gas is The ideal gas constant is R = 8.314 J/mol ∙ K. The change in the internal (thermal) energy of the gas is closest to

A) 0.00 kJ.
B) 12 kJ.
C) 25 kJ.
D) -12 kJ.
E) -25 kJ.