Question $56(1$ point$)$The key difference between an agency shop agreement and an open shop agreement is that in an agency shopworkers must join the union within a stipulated time period $($usually $30,60,$ or $90$ days$)$ in order to keep their jobs, but in an open shop the workers are not required to join the union. the union is restricted to a limited number of employees who perform specific types of jobs, but in an open shop membership in the union is available to all workers.workers who do not join the union must pay a fee or regular dues,