Let u=-2i+6j. Which of the following vectors is orthogonal to this vector? (Hint: Try each choice and see if the vector given is orthogonal to u .) A. 4i +3j B. 2i + 6j C. 2i -6j D. 3i+ j E. 4i+ j F. None of these Given that the vectors u = (1, k) and v = (k2 -8, 2) are orthogonal; find all possible values of k . A. -4, 2 B. 4, -2 C. 0, 4 D. 2, -2 E. -4, -2 F. None of these