Bradley, the production head at Alpha manufacturing Co$.,$ refused to allow the workers into the manufacturing plant while negotiations were taking place for a new collective bargaining agreement. As a result of this action, Bradley helped the owners gain a significant bargaining advantage over the company's labor union. The tactic Bradley followed is an example of a$($n$)\_\_\_\_\_.$

Question $6$ options:

floating lien

runaway shop

closed shop

lockout

abatement