Determine if the following vectors are orthogonal. 2 7 - 7 U= V = 9 15 5 Are the two vectors orthogonal? (Type an integer or a fraction.) O A. The vectors u and v are not orthogonal because u . v = O B. The vectors u and v are not orthogonal because u + v = O C. The vectors u and v are orthogonal because u . v = O D. The vectors u and v are orthogonal because u + v =