During the past week, a local medical clinic tested N individuals for two infections. If 1/3 of those tested had infection A and, of those with infection A, 1/5 also had infection B, how many individuals did not have both infection A and B?
A)  N/15 
B)  4N/15 
C)  N/5 
D)  14N/15 
E)  4N/5