In an Isothermal Process, the Pressure on 1 Mol of an Ideal

In an isothermal process, the pressure on 1 mol of an ideal monatomic gas suddenly changes from 4.00 atm to 100.0 atm at 25°C.
-Calculate w.

A) 0
B) 23.5 kJ
C) 59.5 kJ
D) -59.5 kJ
E) -23.5 kJ