The correct option is C 136a2+2512b3−120c3
(a22+b33−c34)+(2a23+3b34−4c35)+(a2+b3+c3)
Grouping the like terms together,
=(a22+2a23+a2)+(b33+3b34+b3)+(−c34−4c35+c3)
Adding all the like terms,
=3a2+4a2+6a26+4b3+9b3+12b312+−5c3−16c3+20c320
= 136a2+2512b3−120c3