The answer is B .
Biotic factor refers to living things .
D. More economically developed countries
The speed of the cross country runner is equal to 4 km/min.
<u>Given the following data:</u>
To determine the speed of the cross country runner:
Speed can be defined as the distance covered by an individual per unit time and it can be measured in kilometer per minutes (km/min).
Mathematically, speed is given by the formula;

Substituting the given parameters into the formula, we have;

Speed = 4 km/min.
Read more: brainly.com/question/13102821