Explanation : We can use Master theorem to solve this recurrance relation:T(n) = aT(n/2) + Θ(nklogpn)
In given question:
T(n) = 8T(n/2) + Cn
here a = 8 and b = 2 and k = 1.
clearly a > bk
So T(n) = Θ(nlogba )
T(n) = Θ(nlog2 8)
ie T(n) = Θ(n3)
So, option (D) is correct.