question_answer

A line AB in three-dimensional space makes angles \[45{}^\circ \]and \[120{}^\circ \] with the positive x-axis and the positive y-axis respectively. If AB makes an acute angle \[\theta \] with the positive z-axis, then \[\theta \] equals

A)  \[30{}^\circ \]                         

B) \[45{}^\circ \]

C)  \[60{}^\circ \] 

D)  \[75{}^\circ \]

E)  None of these