The correct options are
A nC0+nC12+nC222+⋯nCn2n=(32)11
C nC0−nC12+nC222−⋯+(−1)nnCn2n=(12)11
2n+1C0+2n+1C1+2n+1C2+⋯+2n+1Cn=411
⇒12(22n+1)=222
⇒n=11
Now,
nC0+nC12+nC222+⋯+nCn2n=n∑r=0nCr2r
=n∑r=0nCr(12)r=(1+12)n=(32)n
nC0−nC12+nC222+⋯+(−1)nnCn2n=n∑r=0(−1)rnCr2r
=n∑r=0nCr(−12)r=(1−12)n=(12)n