Which activity is the best example of cardiovascular and strength-training exercises working together?

What are your options? Cardiovascular activity is anything that will raise your heart rate. Strength training is an exercise that builds muscle. 

I’m going to guess these are the choices: a) recreational skiing developed in the mid-19th century b) it was originally invented as a way of getting from place to place in snowy regions c) downhill skiing is currently the only common form of the sport d) it mostly evolved from snowshoeing- if that’s the cases then the answer would be c) downhill skiing is currently the only common form of the sport