The magnitude of vectors $\overrightarrow{\mathrm{A}},\overrightarrow{\mathrm{B}}\mathrm{and}\overrightarrow{\mathrm{C}}$ are 3, 4 and 5 units respectively. If $\overrightarrow{\mathrm{A}}+\overrightarrow{B} =\overrightarrow{C}$, the angle between $\overrightarrow{A} and \overrightarrow{B }$is

• A

  $\frac{\mathrm{\pi }}{2}$

• B

  ${\cos }^{-1}(0.6)$

• C

  ${\tan }^{-1}\left(\frac{7}{5}\right)$

• D

  $\frac{\mathrm{\pi }}{4}$