Suppose that \left(u_{n}\right) is a sequence of real numbers satisfying u_{n+2}=2 u_{n+1}+u_{n}, and that u_{3}=9 and u_{6}=128. What is u_{5} ?

**Answer Choices**

A. 40

B. 53

C. 68

D. 88

E. 104

Suppose that \left(u_{n}\right) is a sequence of real numbers satisfying u_{n+2}=2 u_{n+1}+u_{n}, and that u_{3}=9 and u_{6}=128. What is u_{5} ?

**Answer Choices**

A. 40

B. 53

C. 68

D. 88

E. 104