The correct option is A 9.8N and downward
When the body is at the highest point of its motion its velocity is zero but it is acted upon by the acceleration due to gravity (while it is at rest for a moment at the highest point).
Magnitude of the force on the body at the highest point is given as,
Force, F=mg=1×9.8=9.8N
And, the force due to gravity acts on the body in the downward direction.