If Robert McNamara is one of the options, then he is the correct answer - he was important in the Vietnam War, but not during the WWII.
The answer should be C.
Hope this Helps! :)
External criticism is very important when it comes to analyzing data, because as a researcher it is possible to get too "close" to the data, in that one can stop being objective and start looking for ways to match the data to the desired results.
