Which pair of vectors is orthogonal? Responses A u = ⟨2, 4⟩, v = ⟨-8, 4⟩u = ⟨2, 4⟩, v = ⟨-8, 4⟩ B u = ⟨-1, 9⟩, v = ⟨-9, 1⟩u = ⟨-1, 9⟩, v = ⟨-9, 1⟩ C u = ⟨3, 6⟩, v = ⟨8, 4⟩u = ⟨3, 6⟩, v = ⟨8, 4⟩ D u = ⟨7, 4⟩, v = ⟨4, 7⟩