Standard enthalpy of formation of `N_(2)O_(5)` is `-100 kcal//mol` and standard entorpy of `N_(2),O_(2) " and " N_(2)O_(5)` are 35, 40 and 115 kcal respectively, then `Delta_(r)G^(@)` of following reaction of `227^(@)` C will be :
`2N_(2)+5O_(2)to2N_(2)O_(5)`
A. `-80 kcal`
B. `-180 kcal`
C. `-1800 kcal`
D. `+1800 kcal`