After a labor representative informs her that the union is striking, Jane, the CEO, calls a temp agency to hire replacement workers rather than starting up negotiations with the union again. Why is this an effective tactic against strikes?

Because by doing so$,$ Jane is showing she refuses to give in to union demands, although they legally are required to negotiate prior to hiring replacement workers

Because it's an illegal attempt to break the strike, in that the company can't simply hire replacements

Because it isn't illegal and it allows the company to continue operations

Because it's partially legal, as long as the employees are paid while the strike lasts