If you are given a word of size $n$ bits, the range of $2\text{'}$s complement of binary numbers is

$-2^{n+1}$ to $+2^{n+1}$

c$.,-2^{n-1}$ to $+2^{n+1}$

b$.,-2^{n-1}$ to $+2^{n-1}$

d$.,-2^{n-1}$ to $+2^{n-1}-1$