Which of the following firearms is illegal to own in Kansas?

The correct answer is based on the current legal framework in Kansas regarding firearm ownership. In Kansas, individuals are allowed to possess firearms including automatic rifles and suppressors, provided that they comply with federal laws. Short-barreled shotguns are also legal in Kansas, but they must be registered under the National Firearms Act since they fall under federally regulated firearms.

As such, the statement that none of the firearms listed is illegal to own reflects the reality of Kansas gun laws. Each of the options given can be owned legally, assuming adherence to specific regulations and requirements, such as registration for certain types of firearms. This understanding is essential when considering the legal landscape of firearm ownership in Kansas.