Final answer:
When there is a nerve injury to the left CN IV (trochlear nerve), the head will tilt towards the right side.
Step-by-step explanation:
When there is a nerve injury to the left CN IV (trochlear nerve), the head will tilt towards the right side. This is because the left CN IV is responsible for coordinating the movement of the superior oblique muscle, which helps to rotate the eye downwards and towards the midline. When this nerve is injured, the muscle on the opposite side of the head becomes unopposed and pulls the head towards the damaged side.