Answer:
C. 7.0 × 10¹² red blood cells
Explanation:
First, recall the standard conversion between mm³ and Liters:
[tex]1\text{ Liter}=10^6\text{ mm}^3\text{ }[/tex]Thus, if one cubic millimeter (mm³) of blood contains 7.0 x 10⁶ red blood cells.
[tex]\begin{gathered} 1\text{ Liter=}7\times10^6\times10^6 \\ =7\times10^{6+6} \\ =7\times10^{12}\text{ red blood cells} \end{gathered}[/tex]The correct choice is C.
