Final answer:
The resultant displacement of the car is approximately 8.2 km.
Step-by-step explanation:
The resultant displacement of the car can be found using the Pythagorean theorem. We can consider the displacement in the horizontal direction (west) to be -8 km and the displacement in the vertical direction (north) to be +2 km. Using these values, we can calculate the resultant displacement as follows:
Resultant displacement = sqrt((-8)^2 + 2^2) = sqrt(64 + 4) = sqrt(68) ≈ 8.2 km.
Therefore, the correct answer is D. 8.2 km.