If the Diameter of a Carbon Atom Is Approximately 140 $\times$

If the diameter of a carbon atom is approximately 140 pm,how many carbon atoms lined up side to side would span a pencil lead with a diameter of about 0.7 mm?

A) 5 $\times$ 10¹ atoms
B) 5 $\times$ 10³ atoms
C) 5 $\times$ 10⁵ atoms
D) 5 $\times$ 10⁶ atoms
E) 5 $\times$ 10⁹ atoms