A force is applied to a doorknob. This force will be most effective in causing the door to rotate when which of the following is true?a$)$ The lever arm is parallel to the direction of the force.b$)$ The lever arm length is zero meters.c$)$ The direction of the force is at an angle of $45\backslash$deg with respect to the door.d$)$ The direction of the force is at an angle of $90\backslash$deg with respect to the door.e$)$ The lever arm is perpendicular to the door