When employees protest working conditions by following the employer's rules "to the letter", they are said to be engaged in a:

A) Boycott
B) Corporate campaign
C) Work to rule campaign
D) Letter campaign

A work to rule campaign involves employees adhering strictly to the rules and regulations of their workplace in order to highlight issues or protest working conditions. This usually involves doing only what is specifically stipulated in their job description, and refusing to provide any additional services or work beyond what is required. A boycott involves refusing to participate in a particular activity or purchase a particular product/service. A corporate campaign is a sustained effort by an organization to influence public opinion and government policies. A letter campaign involves contacting individuals or organizations with written correspondence in order to express a particular viewpoint or demand action in a particular area.