Final answer:
The group formed to address the nuclear reactor problem is a task force (option a), a temporary collection of professionals from various disciplines focused on solving a specific issue.
Step-by-step explanation:
The group of engineers, maintenance workers, and mathematicians brought together to solve a nuclear reactor problem and then return to their respective departments afterwards represents a task force. A task force is a temporary group of individuals with different expertise and skills, created for the sole purpose of addressing a specific issue or executing a particular task. Once the task is completed, the task force is usually disbanded. This is differentiated from a temporary committee, functional team, or permanent committee based on the distinct objective and temporary nature of the group's mandate and existence.
In assessing the types of engineers needed, it is clear that since engineered systems have become more complex, dealing with issues such as nuclear reactor problems requires a collaborative effort among professionals from various engineering disciplines. For nuclear reactors specifically, nuclear engineers, mechanical engineers, and electrical engineers might be part of the engineering teams. These teams function within societal structures and are formed to solve complex engineering problems that cannot be addressed by individuals working alone.