Answer
He should make the arrow for “Path” curve downward.
Explanation
The force of gravity is usually directly downward. So from the diagram, it is correctly labelled.
If the object was given a horizontal force, the direction of the inertial is also correct. Inertial is the force the resist the change of state of motion.
What Hector should change is the path followed by the object. It will be a curve not a straight line as it is drawn.
The correct answer is He should make the arrow for “Path” curve downward.