What is the meaning of froth in this passage?

Youth sports have their proponents and, on the other hand, their opponents. In my opinion, sports temper a person’s spirit, making him or her resilient and durable, just as steel is tempered. Those who froth at the mouth at the suggestion of youth sports are burbling in vain.

Responses

things that will soon disappear
things that will soon disappear

a light, bubbly liquid
a light, bubbly liquid

to spill over with foam
to spill over with foam

unimportant topics or comments

1 answer

none of the above