Please guide me for 54th question... Also I would like to know a method to solve multinomial terms...thank you

we can solve this types of questions without any method by shortcut here in this question just put n=1 and then it become 1+x+x²now a₁=1 a₂=1 so will get 1-2=1 now if n=1 option 2 is correct (at n=1 its is 1 only other are 0 ,-1 ,2)