Vectors $\overrightarrow { \mathbf { A } }$ And $\vec { B }$

Multiple Choice

Vectors $\overrightarrow { \mathbf { A } }$ and $\vec { B }$ are shown.What is the magnitude of a vector $\overrightarrow { \mathrm { C } }$ if $$\overrightarrow { \mathrm { C } } = \overrightarrow { \mathrm { A } } - \overrightarrow { \mathrm { B } }$$ ?

A) 46
B) 10
C) 30
D) 78
E) 90