Final answer:
During the Cold War, the 'trouble makers' at Warner Bros. were individuals accused of having Communist backgrounds or sympathies. The Hollywood Ten, a group of ten individuals who refused to testify before the House Committee on Un-American Activities, were among the most prominent 'trouble makers' at Warner Bros.
Step-by-step explanation:
The 'trouble makers' at Warner Bros. referred to individuals who were accused of having Communist backgrounds or sympathies during the Cold War era. These individuals were targeted by the House Committee on Un-American Activities (HUAC) and faced consequences such as being blacklisted from the industry. The Hollywood Ten, a group of ten individuals who refused to testify before HUAC, were among the most prominent 'trouble makers' at Warner Bros.