Whats the assumption of the author about smoking restriction according to the last paragra

Whats the assumption of the author about smoking restriction according to the last paragraph？

A．People can try out some gentler smoking bans.

B．The municipality could try extending the smoking bans to homes.

C．It will not be a personal choice to decide whether or not to smoke.

D．It must still be necessary to restrict smoking after several generations.

请帮忙给出正确答案和分析，谢谢！