Which of the following factors should be considered when designing a personal fitness program? a. goals b. activities c. variety d. all of the above

D. All of the above,because they all important.

D. all of the above that's answer 

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