The resultant of \( \vec{P} \) and \( \vec{Q} \) is perpendicular to \( \vec{P} \). What is....

Question The resultant of \( \vec{P} \) and \( \vec{Q} \) is perpendicular to \( \vec{P} \). What is the angle between \( \vec{P} \) and \( \vec{Q} \) ?
(A) \( \cos ^{-1}\left(\frac{P}{Q}\right) \)
(B) \( \cos ^{-1}\left(\frac{-P}{Q}\right) \)
(C)  \( \sin ^{-1}\left(\frac{P}{Q}\right) \)