Which Set of Gases Is Listed from Slowest to Fastest $\lt$

Which set of gases is listed from slowest to fastest diffusion rate?

A) HCN $\lt$ H₂ $\lt$ He $\lt$ O₃
B) H₂ $\lt$ He $\lt$ HCN $\lt$ O₃
C) O₃ $\lt$ HCN $\lt$ He $\lt$ H₂
D) HCN $\lt$ He $\lt$ O₃ $\lt$ H₂
E) H₂ $\lt$ HCN $\lt$ He $\lt$ O₃