Vectors and coordinates (Components of a vector)

In diagram below two vectors A\vec{A}and B\vec{B} have shown. VectorsC\vec{C}and D\vec{D}are the sum (A+B)\left(\vec{A}+\vec{B}\right) and difference (AB)\left(\vec{A}-\vec{B}\right)vectors, respectively.
Which statement is correct about the magnitude of four vectors?
More Length of a Vector (Vector Norm) Questions: