Two planes are perpendicular to one another. One of them contains vectors A and B, and the other contains vectors C and D. Which of the following relationships holds true?
A) A ⋅ C + B ⋅ D = 0 B) A ⋅ D - B ⋅ C = 0 C) A ⋅ B + C ⋅ D = 0 D) A ⋅ D + B ⋅ C = 0