5. Choose the correct big-O estimations of the following functions. (12 points) (1) T(n) = n*Vn/2 + 5n*log(n) is (a) (n* n) (b) (n*log(n)) (c) (n) (d) P(n) (2) T(n) = 5n*log(n) +4n is (a) (1) (b) (n) (c) O(log(n)) (d) O(n*log(n)) (3) T(n) = (n+1)(n+2)/2 + 1 is (a) O(n) (b) O(n) (c) nh) (d) O(n*log(n))