A mass ‘m’ of a perfect gas at pressure p1 and volume V1 undergoes an isothermal process. The final pressure is p2 and volume V2. The work done on the system is considered positive. If R is the gas constant at T is the temperature, then the work done in the process is

• A. \({p_1}{V_1}\ln \frac{{{V_2}}}{{{V_1}}}\)
• B. \( - {p_1}{V_1}\ln \frac{{{p_1}}}{{{p_2}}}\)
• C. \(RT\ln \frac{{{V_2}}}{{{V_1}}}\)
• D. \( - mRT\ln \frac{{{p_2}}}{{{p_1}}}\)