You have vector [tex]\vec{a}=(-3,2).[/tex]
The magnitude of the vector [tex]\vec{a}=(x_a,y_a)[/tex] can be obtained using formula:
[tex]|\vec{a}|=\sqrt{x_a^2+y_a^2}.[/tex]
Then
[tex]|\vec{a}|=\sqrt{(-3)^2+2^2}=\sqrt{9+4}=\sqrt{13}.[/tex]
Answer: correct choice is A.
