Final answer:
The distance covered by the girl is approximately 84.85 km.
Step-by-step explanation:
To determine the distance covered by the girl, we can use the Pythagorean theorem. The girl walks 60 km eastward and due north, which forms a right triangle. The distance covered can be found by finding the hypotenuse of the triangle. Using the Pythagorean theorem, we can calculate the distance as follows:
Distance = sqrt((60 km)^2 + (60 km)^2)
Calculating the equation gives us:
Distance ≈ 84.85 km
Therefore, the answer is not listed in the given options.