AMC 10B 2007 Problem 24

Let n denote the smallest positive integer that is divisible by both 4 and 9 , and whose base-10 representation consists of only 4’s and 9’s, with at least one of each. What are the last four digits of n ?

Answer Choices
A. 4444
B. 4494
C. 4944
D. 9444
E. 9944