Final answer:
Based on the provided references, the boys were likely agitated due to stress related to an upcoming exam, as the context points to academic pressures and a hurried learning environment.
Step-by-step explanation:
The boys were likely in an agitated mood because they were anxious about an upcoming exam. The evidence provided in the passages outlines various scenarios where agitation might arise, such as during schoolroom chaos, a personal argument, the imminent challenge of public speaking, or an escape attempt fraught with nerves. While options A and D are not supported by the context of agitation, option B could be a potential cause; however, it is not explicitly linked to the mood of the boys. Instead, option C is the most consistently supported by the reference to a 'smart application' to quicken their speed, suggesting the stress of academic performance and the hurried nature of their lessons.