The correct option is A True
(1+x)n=C0+C1x+C2x2+...+Cnxn
MUltiplying both sides by X,
x(1+x)n=C0x+C1x2+C2x3+...+Cnxn+1
Differentiating both sides
(1+x)n+xn(1+x)n−1=C0+2.C1x+3.C2x2+...+(n+1)Cnxn
putting x=1, we get
C0+2.C1+3.C2+...+(n+1)Cn=2n+n.2n−1
C0+2.C1+3.C2+...+(n+1)Cn=2n−1(n+2)