What disperses oxygen rich blood throughout the body?

The __ circulation disperses oxygen rich blood throughout the body. blood cells bring oxygen to cells and take carbon dioxide away. ___ transfer waste-filled blood from tissues into the pulmonary circulation. The main organ of the respiratory system is the .

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

Ithink it’s d. that should be correct.