Final answer:
Signed authorization cards are accurate predictors of the number of votes for the union in elections. Option (a).
Step-by-step explanation:
The statement that signed authorization cards are accurate predictors of the number of votes for the union in elections is true(a).
When a group of workers want to form a union in the United States, they set an election date and the employees vote in a secret ballot. Employers use signed authorization cards to determine the number of votes in favor of the union, indicating that these cards are indeed accurate predictors.
For example, if a company has 100 employees and 75 of them have signed authorization cards, it is likely that a majority will vote in favor of the union, based on the high percentage of employees who have already expressed their support through the signed cards.