The angle between vector ( → A ) and ( → A - → B ) is :

Options

1. A$\tan^{- 1}\left(\dfrac{Bcos\theta}{A - Bsin\theta}\right)$
2. B$\tan^{- 1}\left(\dfrac{\sqrt{3}B}{2A - B}\right)$
3. C$\tan^{- 1}\left(\dfrac{- \dfrac{B}{2}}{A - B\dfrac{\sqrt{3}}{2}}\right)$
4. D$\tan^{- 1}\left(\dfrac{A}{0 . 7B}\right)$