Twenty one participants from four continents (Africa, America, Australia, and Europe) attended a United Nations conferencE- Each participant was an expert in one of four fields, labour, health, population studies and refugee relocation. The following five facts about the participants are given.
A- The number of labour experts in the camp was exactly the half the number of experts in each of the other three fields.
B- Africa did not send any labour expert. Otherwise every continent, including Africa, sent at least one expert in each categories.
C- None of the continents sent more than three experts in any category.
D- If there had been one less Australian expert, then the America would have had twice as many experts as each of the other continents.
E- Mike and Alfonzo are leading experts of population studies who attended the conferencE- They are from Australia.
Which of the following numbers cannot be determined from the information given?