I believe the answer is: c. airplanes, farming
During the wartime, airplanes industries managed to develop the technology that allow the planes to move at higher elevation and speed, which would give a competitive advantage during the war.
The development in farming revolve around their preservation technique, which made is easier for the government to prepare the meal supply for their soldiers.
I believe it might be Ford (Henry J. Ford).
Answer:
A. A print or online encyclopedia
C. A government agency's website (ending in .gov)
D. A journal, letter, or other primary source
Reflecting on whether a adding a salad bar to a school lunch menu fixed a problem is an example of EVALUATING A SOLUTION.
For every decision that one makes, there is a need to consider the pros and the cons of the decision in order to ensure that resources are used judiciously. When a problem has been identify and solved, there still remains a need to check whether the solution used effectively take care of the problem, this is what is called evaluation.
In the question given above, considering whether adding a salad bar to the school menu fixed a problem is an example of evaluating a solution.
The answer to you question would be C.
hope this helps