What Is the Key Difference Between Small Compressed Gas Cylinders

Multiple Choice

What is the key difference between small compressed gas cylinders (sizes AA to E) and their larger counterparts (sizes F to K) ?

A) Small gas cylinders do not undergo regular DOT testing.
B) Small gas cylinders are always filled to lower pressures.
C) Small gas cylinders cannot be used for anesthetic gases.
D) Small gas cylinders use a yoke (not threaded) connector.