During the 1920s and early 1930s, the Rosedale Shoe Factory was able to prevent workers from forming a union by requiring them to sign an employment contract in which they agreed not to join a union as a condition of employment. Rosedale Shoe Factory was making use of .a. yellow-dog contracts.
b. blacklisting agreements.
c. injunctions.
d. implied consent decrees.

Option a==> yellow-dog contracts.

Explanation:

In the United States of America, there was a period( 1920s and early 1930s) that in order to secure a job, the employees has to come into aggreement with the employers that they will never form or join any union relating to labour. This case was very rampant in the public sector of the economy in which people seeking for work has to give up their rights to protest for unjustice ( for example teachers during those times were not to join any labour union).

The reason behind yellow-dog contracts is to make sure that employers are able to stop workers from protesting.

Therefore, we can see from the Explanation above that Rosedale Shoe Factory was making use of yellow-dog contracts.

speed

explanation:

yeet yeet yeet yeet yeet yeet yeet yeet yeet yeet