You are presented with the question "What transports oxygen?" and the following answer choices: 
- Hemoglobin
 - hydrocarbons
 - orchids
 - roots
 - alpacas
 - burning coal
 - lungs
 - mammals

Now knowing that oxygen is just one substance transported by the blood and hemoglobin transports oxygen in blood, choose the best answer.


 

 Hemoglobin        