When we are solving option (c) $T(n)=2T(n-1)+1$ the solution will be $T(n)=2^{n+1}-1$, which is exponential order. (This is the recurrence corresponding to Tower of Hanoi).
and by applying masters theorem to others we will get Option (A) is $n^2$, option(B) is $n$ and option(D) is $n^3$
Answer is C