Final answer:
The 'blank organization' mentioned refers to the Construction organization, where member contractors provide both physical labor and mental planning to tackle complex projects.
Step-by-step explanation:
The blank organization and member contractors in the context of the sentence provided is most likely referring to option B) Construction because contractors are often associated with construction work. These contractors have long practiced constructive solutions to solve complex engineering problems within societal structures. Large construction projects, such as the building of pyramids or cathedrals, involve not only the physical labor of contractors but also their mental skills in organizing blueprints, adhering to building codes, and operating complex machinery. This blend of physical and mental effort is required in much the same way that a surgeon combines both types of skills in their work.