As people age they become an able to control their cardiorespiratory fitness

No that is incorrect because as the people we getting older, their cardio respiratory shorter than the young ones and their bones are getting weaker, which might permanently break their bones. In some cases they might not able to walk again.

Yes you do , which is cool

Bmust be the answer, as technically all organs move, so a is incorrect. all organs are made of different types of cells, so that isn’t a problem, so c is also incorrect. human hearts are very similar to many other animals’ hearts, so d is also incorrect, yet the heart is made of muscle, which is hard to grow in the lab so it would be correct to say b