Which sentence from the article best supports the idea that penny licks were to blame for making people sick?

[Cones] remain crowd-pleasing containers for a scoop or two on the go.
[People] served tiny scoops of ice cream in a glass container.
Germs were easily passed from one customer to the next.
The penny lick's downfall helped bring about the ice cream cone.

Germs were easily passed from one customer to the next.