Among the Conclusions of Chapter Eight's Survey of the Evidence

Among the conclusions of Chapter Eight's survey of the evidence on international technology transfers is that:

A) The volume of bilateral trade is able to explain a large part of the variation in bilateral technology flows.
B) the overall rate of diffusion has slowed markedly since World War II.
C) developing economies absorb more foreign technology than developed economies.
D) All of the above.
E) Only a and c above.