In the following P-V diagram two adiabatics cut two isothermals at temperatures T1 and T2 (fig.). The value of \[\frac{{{V}_{a}}}{{{V}_{d}}}\] will be

• A.            \[\frac{{{V}_{b}}}{{{V}_{c}}}\]                                          
• B.            \[\frac{{{V}_{c}}}{{{V}_{b}}}\]
• C.            \[\frac{{{V}_{d}}}{{{V}_{a}}}\]                                          
• D.            \[{{V}_{b}}{{V}_{c}}\]