Suppose vectors ⃑ 1 = 2( + )and⃑⃑ 1 = 2 + 3 + , which of the following is unit vector perpendicular to both vectors. A. 1 √2 (− + + ) C. 1 √3 ( + + ) B. 1 √3 ( − + ) D. 1 √2 ( − ‐