n moles of an ideal gas with constant volume heat capacity Cv undergo an isobaric expansion by certain volume. The ratio of the work done in the process, to the heat supplied is:

• A. \(\frac{{{\rm{nR}}}}{{{{\rm{C}}_{\rm{V}}} + {\rm{nR}}}}\)
• B. \(\frac{{{\rm{nR}}}}{{{{\rm{C}}_{\rm{V}}} - {\rm{nR}}}}\)
• C. \(\frac{{4{\rm{nR}}}}{{{{\rm{C}}_{\rm{V}}} - {\rm{nR}}}}\)
• D. \(\frac{{4{\rm{nR}}}}{{{{\rm{C}}_{\rm{V}}} + {\rm{nR}}}}\)