Let <span class="math-tex">\(\vec a\)</span> and <span class="math-tex">\(\vec b\)</span> be two vectors, which of the following vectors are not perpendicular to each other?
(A) <span class="math-tex">\(\left(\vec a \times \vec b\right)\)</span> and <span class="math-tex">\(\vec a\)</span>
(B) <span class="math-tex">\(\left(\vec a + \vec b\right)\)</span> and <span class="math-tex">\(\left(\vec a \times \vec b\right)\)</span>
(C) <span class="math-tex">\(\vec a + \vec b\)</span> and <span class="math-tex">\(\vec a - \vec b\)</span>
(D) <span class="math-tex">\(\vec a - \vec b\)</span> and <span class="math-tex">\(\vec a \times \vec b\)</span>