The North American and European continents are moving apart at a rate of about 3.0 cm/yr. At this rate, how many years will it take them to drift 500.0 km farther apart than they are at present?

a) 1.67 x 10⁷ years
b) 1.67 x 10⁹ years
c) 1.67 x 10⁶ years
d) 1.67 x 10⁸ years
e) 1.67 x 10¹0 years