The following geometric sequences represent the populations of two bacterial cultures at the 1-hour mark, the 2-hour mark, the 3-hour mark, and so
on. Culture A starts with more bacteria, but culture B has a ratio of increase
that is larger. Which culture will have the greater population at the 18-hour
mark?
Culture A: 400, 600, 900, 1350,...
Culture B: 5, 10, 20, 40,...

A. Culture A
B. Culture B