A local bookseller carefully collects data on the customers that enter her store. She uses the term "unit" to describe either a customer that comes in alone or a group of customers that come in together. Based on past experience, she estimates that 13% of the units who enter her store will make some type of purchase. It appears that the units are independent. What is the probability that three units in a row will make a purchase? Choose the correct answer below.
A.0.13
B.0.39
C.0.002197
D.0.169