B. because they are not manufactured by the body
IF:
Number of cells:

DNA lenght:

Distance from Earth to Sun:

Then:
a) <span>Over how many miles would the total DNA from the average human stretch?
The answer is product of multiplication of the number of cells (C) and the DNA length (D):
Total DNA: </span>

⇒

⇒

⇒
The total DNA from the average human will stretch 
b) How many times would the total DNA from the average human stretch from Earth to the Sun and back?
The answer is concluded from the ratio of the total DNA length (T) and the <em>twice </em>(because of stretch to the Sun and back, thus, <em>two directions</em>) of distance from <span>Earth to the Sun (ES) and :
Ratio: </span>

⇒

⇒

⇒

<span> ⇒

</span><span> ⇒ [tex]R = 667.7
</span>
Thus, 667,7 times will the <span>
total DNA from the average human stretch from Earth to the Sun and back.</span>
Mitochondria, using oxygen available within the cell convert chemical energy from food in the cell to energy in a form usable to the host cell.