Answer:
F = 20 N south
Step-by-step explanation:
It is given that,
Force applied on the racing car in south direction is 30 N and parachute deploys resulting in a 10 N force due North.
We need to find the net force on the car.
Let North denotes +y axis and South denotes -y axis.
So, F₁ = +10 N
F₂ = -30 N
Net force is :

It means that the net force is 20 N and it is acting in south. Hence (d) is correct.