Which term does not belong with the other three?

a. strike

b. strikebreaker

c. strike fund

d. picket line

The term which does not belong with the other three is b) strikebreaker. A strikebreaker is someone who works despite his company protesting against their working conditions or the company they are working for. Strikebreakers are often seen as people who have been employed after or during the strike. This does not fit in the lexical field as do the other ones, because all the others relate to strikes, and this is a person who would be considered an outsider of a strike.